Original subtitles

Narrator: A mysterious lake

deep beneath the city of chichen itza.

A secret mountain trail

that disappears high above machu picchu.

Lost pyramids covered by the jungles of guatemala.

The wonders of the ancient americas

are still brimming with new discoveries.

Every day is different in machu picchu.

Every minute is different in machu picchu.

Narrator: Seven legendary monuments

defined the ancient americas.

Now investigators use innovative laser technology

to strip away the forests that cover them

and reveal new images in the desert.

This lets us see the maya ruins in a way that we never thought possible.

Narrator: How did the ancient americans

build such remarkable monuments?

And why do they look so similar to the wonders of the old world?

To solve these mysteries, we'll blow apart

mighty pyramids.

We'll lift up gigantic stone heads

from the jungle

and crack the secret code behind the bizarre nazca lines.

Seven astonishing wonders will reveal the rise of civilization

in the ancient americas.

-- Captions by vitac -- www.Vitac.Com

captions paid for by discovery communications

♪

the americas, 1492.

Three spanish ships led by christopher columbus

arrive in the new world.

Here, europeans encounter wonders

beyond their imagination --

mighty pyramids, vast cities, and temples covered in gold.

Incredibly, the people of the americas

build their wonders without the technology

used in the old world.

They don't use the wheel, metal construction tools,

or even beasts of burden.

How do they engineer incredible megastructures

that rival the monuments of ancient egypt, babylon,

and greece?

A clue lies with the first wonder,

in modern-day mexico --

the stepped pyramid of chichen itza.

A thousand years ago,

this is a powerful, working city,

home to 30,000 people,

the greatest metropolis of the ancient maya.

A civilization known for its remarkable skill

in astronomy, mathematics, and architecture.

Archeologists like memo de anda

are still making new discoveries at this mysterious jungle city

and its awe-inspiring buildings.

Hidden in an ancient mayan temple,

a limestone altar engraved with scenes of human sacrifice

and a lost cave beneath the metropolis,

untouched for a thousand years,

filled with offerings to the gods.

And 15 miles outside the city,

aerial laser scans reveal the true extent

of a mayan superhighway

that connects the nearby cities of coba and yaxuna.

But chichen itza's famous pyramid

remains one of the most mysterious of all.

It contains many secrets,

despite more than 100 years of archeology.

We're just scratching the surface.

That's literally what we're doing.

I'm sure this building is still hiding

many, many secrets inside.

Narrator: Later, nicknamed "el castillo,"

spanish for "castle,"

its beauty rivals, the great pyramid of giza.

Built from tens of thousands of limestone blocks,

it towers nearly 100 feet high, as tall as a 10-story building.

At its peak, a sacred temple

dedicated to the serpent god, kukulkan.

On each side, steep steps that reflect the maya calendar.

And at the base, snakeheads.

How did ancient engineers build this 60,000-ton structure?

♪

the pyramid we see today

is at least a thousand years old.

It shares many similarities with those in egypt,

despite being more than 7,000 miles away.

Like the great pyramid,

the oldest of the original seven wonders,

it is made from limestone.

Chichen itza's design

also resembles the stepped pyramid of saqqara

and the tower of babel in iraq.

But the ancient americans who build it

only have stone construction tools,

unlike their counterparts in ancient egypt,

babylon, or greece, who use metal.

How do the maya construct this stone giant

with the technology available to them?

The first step is to find the limestone.

Memo searches for it in the jungle that covers the city.

♪

de anda: The maya didn't have to really go far away

to find the material to build their big cities.

Limestone -- it's everywhere.

The material is beneath their feet --

all this material is right there.

Narrator: The limestone lies within very easy reach.

The soil is very, very thin.

It's not even two centimeters of soil

that's laying over the huge limestone bedrock.

It's limestone all around us.

It's actually the whole peninsula.

It's a big limestone platform.

Narrator: Limestone is the crucial ingredient that allows

the maya to construct chichen itza's great buildings.

But where do workers mine it?

Just over a quarter of a mile from the castillo pyramid,

memo uncovers extraordinary evidence of a quarry.

Right here, we can see a pre-form.

It's a huge piece of rock -- of limestone --

that they started working.

'cause, see, this is perfectly round,

and we can see on one side the start of the formation

of a mouth of a snake.

But somehow, they leave it here.

Maybe because it got broken.

Narrator: Maya craftsmen

carved this huge block a thousand years ago.

De anda: And it shows us by being here

is that they obtained the material,

and they work it right here.

They take it when it was finished up to the city.

So that's pretty amazing.

Narrator: The local geology provides chichen itza's builders

with an endless supply of limestone.

But without metal tools,

how do they lift the stone out of the ground?

Archeologists think the builders of the egyptian pyramids

used copper chisels, drills, and saws.

The builders of babylon

have even stronger tools made of iron.

De anda: It is interesting,

and it's amazing at the same time.

How can they build these fantastic cities

only with stone tools?

One theory is that the resourceful maya came up

with an ingenious solution.

They use shards of razor-sharp stones, like chert,

sometimes attaching them to wooden sticks.

They gouge deep channels into the ground,

carving a checkerboard pattern into the limestone.

The workers dig down until they reach a natural break

in the limestone bedrock.

This way,

the checkerboard blocks crack away from the ground.

Then they use wooden levers to pry the blocks out.

♪

to test this idea,

memo heads to a stonemason's yard in merida,

around 70 miles from chichen itza.

♪

the stonemasons attempt an experiment.

They will use wooden levers

to try to extract a two-ton limestone block,

just as the ancient maya would have done.

De anda: All the stones they put there to make a lever.

I think we put a little bit too many.

So we need space for the big lever.

These guys are extraordinarily skillful and strong.

I mean, they're great.

So far, so good.

[ laughs ]

narrator: Shifting the limestone the old fashioned way

requires both technique and plenty of strength.

De anda: Today, that I have the opportunity

to move this relatively small stone

and it was so hard.

And there were a lot of people,

I realized how hard it was.

And I'm getting more and more and more respect for the maya,

for what they do.

It's amazing.

Wow, that was great.

[ laughs ]

these guys are great.

[ applause ]

wow.

Narrator: The maya

rely on human power alone to build their pyramids.

In ancient egypt, the pharaohs similarly use armies of workers

to drag the heavy stone blocks they need.

But they also have beasts of burden like cattle,

which do not exist in the americas.

The ancient greeks who build the temple of artemis

or the lighthouse of alexandria use levers and pulleys.

The architects of the new world and the old

use different tools and techniques

to construct their wonders.

But, incredibly,

they all create similar-looking monuments.

The great pyramid at chichen itza

is just one of hundreds

that cover mexico and central america.

There are more pyramid structures

in the americas than egypt.

Why are civilizations on opposite sides of the globe

obsessed with these buildings?

What are they all for?

New technology reveals an astonishing secret

hidden deep beneath chichen itza's pyramid.

And what are these giant stone heads

concealed in the jungle?

Narrator: The huge stepped pyramids of mexico

are incredible wonders.

These engineering marvels define the ancient americas.

But they share many remarkable similarities

with those in egypt and babylonia.

Why do people with no knowledge of each other

build the same megastructures?

In egypt, almost all pyramids are tombs.

The great pyramid of giza,

the first wonder of the ancient world,

is the final resting place for a pharaoh called khufu.

But its american cousin at chichen itza is very different.

The pyramid at chichen itza

is a temple brimming with symbolism.

It serves as a monumental calendar for the city.

18 stone terraces represent the 18 mayan months of the year.

91 steps on each side, plus the top platform,

give 365 steps,

one for each day of their year.

And twice a year on the equinox,

the sun casts a shadow so perfectly aligned,

an immense snake appears to slither down the main steps.

This is the serpent god, kukulkan,

to whom the temple is dedicated.

It's hard to understand how they could master the technique,

not only to build this fantastic building,

but to make it so beautiful,

so interesting, and relate it to the sun,

to relate it to the changes of seasons.

It's great.

Narrator: The shape and function of the american pyramids

have more in common with ziggurat temples

like the tower of babel

than the pyramids of egypt.

Both structures soar to the heavens.

But chichen itza also hides an incredible secret beneath it.

New radar technology strips away

the pyramid's thick limestone shell

and peers through a layer of rubble

to reveal how it stands

on top of a giant underground cave full of water,

a formation known as a cenote.

The cave contains as much water as six olympic swimming pools.

It extends more than 65 feet underground.

This new discovery

is one of the most stunning finds in mayan archeology.

Could the existence of this hidden lake

explain why the pyramid is here?

Without digging, there's no way to access the cenote.

Archeologists hunt for a tunnel that might lead to it.

But there is more than one cenote in the area

around chichen itza.

Archeologist memo de anda

investigates nearby cenote holtun.

Ready to go.

Narrator: The only way

to explore this hidden lake is to dive.

The way in is a vertical abseil into the dark.

This is not for the faint-hearted.

The vast cavern extends over 220 feet down.

It contains a large underground lake.

More than 160 feet deep.

De anda: Going down in a cenote

is one the best experiences in the world.

♪

narrator: More than 6,000 underground lakes exist

in this part of central america alone.

De anda: We're about 8, 9 meters down

and can see the cultural richness of this place.

♪

and I don't want to approach too close

because it can destroy everything in a second.

Narrator: Memo is making some astonishing discoveries --

ceramic offerings, animal bones, and human remains,

left here when the water level is lower.

Each time he dives into this cenote,

memo takes high-resolution photographs.

This cenote is a sacred place for the maya.

De anda: Right in front of me, you can see a shelf.

It's a natural shelf, ideal to make a ritual deposit.

Narrator: More bones, other offerings

and even traces of charcoal remain on this shelf.

Amazingly, it appears this platform is once a sacred altar.

De anda: This is part of the spiritual world.

Cenotes are silent witnesses of very important part

of the ancient maya life.

This is a very important part of their universe.

[ conversing in spanish ]

narrator: Memo has found some truly extraordinary evidence

about the rites conducted in this cenote.

De anda: It's was a very, very nice dive,

and I think we get what we needed.

Narrator: Memo has been photographing this site

for five years.

A custom-made computer program

processes the photos taken so far

and turns them into astonishing,

three-dimensional models of his discoveries.

De anda: What I'm looking at right now,

it's a bird's-eye view of the whole shelf.

This is an amazing, amazing image.

Is the next best thing of having an object in my hand.

And the beauty of this is that we leave them there.

Narrator: These objects

are probably offerings to the rain god.

There's no way of knowing if similar ones lie

in the cenote beneath el castillo.

But archeologists think these underground lakes

are sacred to the maya.

De anda: This is el castillo, or kukulkan temple.

One of the things that's amazing about this building

is that it's situated right in the middle of four cenotes.

It's the sacred cenote to the north,

the xtoloc cenote to the south,

sagrado cenote to the east,

and holtun cenote to the west.

Narrator: The ancient maya divide their universe

into quadrants.

These were aligned with the four points of the compass.

Could chichen itza's layout be

a physical representation of the maya universe?

So if you draw two lines,

the center of those lines is el castillo.

El castillo was built there

because the orientation of those four cenotes.

Narrator: How the ancient maya know

about the fifth cenote under the castillo remains a mystery,

but memo believes they do

and that the great pyramid is built on this site

because it symbolized the center of the maya universe.

De anda: When they said there is a cenote under the castillo,

and you see it's the center of this sacred alignment,

it makes a lot of sense.

Narrator: The pyramid builders of the americas

share a common dream

with those in egypt or babylon.

Shaped by their own unique beliefs,

they all build monuments worthy of the gods

that reach towards the heavens.

But the way the mayans use their pyramids

is far from unique in the ancient americas.

Many other cultures, like the aztecs,

build pyramids, too, and believe in a serpent god.

Could a single mother culture be responsible for them all?

Where does civilization in the americas begin?

The answer lies with the next great wonder --

gigantic stone heads buried in the jungle of central mexico.

And how many more lost cities are waiting to be found?

♪

narrator: The seven wonders of the ancient americas

span thousands of miles and hundreds of years.

But could one civilization be the inspiration

for many of the cultures that build them?

A clue lies with the second wonder, on mexico's gulf coast.

The statues of la venta.

Today, jungle covers most of this site,

but at its peak 3,000 years ago,

la venta is a thriving metropolis

built by a mysterious people called the olmecs.

They lived thousands of years before the mayan

and aztec civilizations of mexico.

And at la venta, they leave behind an astonishing wonder.

Buried beneath the ground at the heart of the city,

archeologists unearth an enormous stone head

carved entirely from a single boulder.

Nearby, they discover two more.

Each statue stands over seven feet high,

weighs up to 20 tons, and wears the same mysterious headgear.

What are these 3,000-year-old figures?

Could the answer reveal how civilization

begins in central america?

♪

wow, when you walk up to these things,

it's right there in your face.

They're massive.

You can stare right into their eyes, and, I mean,

you can really tell that this was an individual.

This is a person.

Narrator: Archeologist carl wendt hunts for answers.

He starts by investigating the material

the heads are made from.

They're all basalt,

a type of rock not found at la venta.

Wendt: Why would they carve this stone?

You can't find this stuff anywhere around here.

Bringing this stuff in for a particular reason,

this was important.

And where they actually got this rock from

is going to tell us a lot.

Narrator: Carl believes

that tracking down the source of the basalt

will reveal why the olmecs carved the statues

and what they represent.

He travels 60 miles north of la venta

into the tuxtla mountains.

Today, it's a short ride on the highway,

but for the olmecs, it's a three-day uphill hike.

♪

here, giant basalt boulders cover a vast area.

Carl scours the site for proof

la venta's heads come from this spot.

Pushing deeper into the jungle,

he investigates an extraordinary discovery.

Wendt: Oh, man.

I've never seen anything like this before.

This is one of a kind.

This is a pre-form of an olmec colossal head.

They would have carved the headdress.

Then you would come down to the face, to the nose.

And finally, the mouth.

This is the exact same size

as some of the colossal heads at la venta.

I mean, it's a dead ringer.

With a few more weeks' work,

this stone could've ended up at la venta.

Narrator: Basalt holds a special meaning for the people

who carve the heads.

This rock is the product of volcanic eruptions,

a natural event

the olmecs consider the work of the gods.

Wendt: Mountains and volcanoes,

especially, are significant in olmec religion.

And for these boulders, then, to be thrown out of the volcano

and strewn throughout this area, the material itself

would have had symbolic religious significance.

And the people whose images were carved into these monuments,

they were aligning themselves with the deities.

Narrator: Carl believes only la venta's elite receive

this honor.

Wendt: These are almost certainly

the faces of the priest-kings,

the leaders of the site of la venta.

Narrator: Incredibly, there is evidence these people could be

the first royal family in the americas.

Wendt: While the faces are different,

we have a certain template that all these heads follow --

the ear spools, the headdress, the helmet.

And for the similarity of design,

it could be that these individuals were related

and represent not just a succession of rulers,

but possibly the first dynasty.

Narrator: The olmecs rise to power around 1,200 b.C.

They live at the same time

as the new kingdom pharaohs of egypt,

who also commissioned giant statues of themselves.

At la venta,

they build the first planned city in ancient mexico.

La venta has it all --

fertile soils for growing crops,

rich fish stocks and forests for sourcing building materials.

Because the area is blessed with so many resources,

fewer people are needed to produce food to feed the city.

So la venta's inhabitants can do new jobs

like building huge pyramids.

The olmec lay down the template for other cities

in central america.

La venta becomes mexico's cradle of civilization.

Wendt: The olmec should be remembered

for their sophistication.

They moved hundreds of tons of stone

through tropical rainforest.

They built cities out of mud.

They developed a sophisticated religion and symbol system.

The more we learn about the olmec,

the more we're learning about the foundations

of mesoamerican society.

Narrator: Today, the olmec civilization

lies buried in the jungle.

But archeologists are using new technology

to peer beneath the trees.

Could discoveries at the next wonder

reveal the true extent of civilization

in the ancient americas?

And are the maya the victims of their own success?

♪

narrator: More than 2,000 years ago,

a revolution sweeps across the ancient americas.

Inspired by the mysterious olmec civilization,

people build hulking pyramids at cities across mexico

and central america.

But the third wonder lies hidden deep

in the jungles of guatemala --

the mayan city of tikal.

Peeling away the foliage reveals the center

of a once fabulous metropolis.

Incredible limestone palaces sit next to slender pyramid temples,

some towering over 200 feet tall.

Giant stone slabs commemorating tikal's rulers

border sweeping plazas.

Tikal is home to the finest concentration

of mayan architecture in the americas.

Could there be even more concealed by the jungle?

Archeologist tom garrison believes

we've only scratched the surface

of what lies hidden here.

Garrison: In my archeology,

it's relatively easy to find the cities.

They have these massive pyramids

that stick out of the jungle canopy.

But as you move further

and further outside of this central area,

the city becomes buried under this weight of jungle.

And it becomes very difficult to determine just how vast

and how extensive a place like tikal really was.

Narrator: Previous attempts by investigators

to understand the scale of tikal

by hacking through the jungle prove impossible.

But now a pioneering new technique gives tom the edge.

It uses special laser-scanning technology called lidar

to see through the trees.

A plane-mounted sensor shoots laser beams

through the jungle canopy to the floor,

building a picture of the lost areas of the city.

Garrison: What this allows us to do

is essentially digitally deforest the jungle.

And this lets us see the maya ruins underneath in a way

that we never thought possible.

So now we can see more of tikal.

Narrator: Lidar peels back over a thousand years of history

to reveal what tom's been searching for.

Garrison: We can see the map of the site's core crystal clear.

We can see the distinctive shape of tikal's road systems.

Narrator: Lidar reveals a sprawling road network

encompassing an area of 16 square miles.

The roads lead

to previously undiscovered parts of the city --

temples, fortresses, and residential districts.

There are thousands of structures out there

in the jungle that would have been the houses

of the everyday people that made up most of the population.

The lidar data over tikal revealed

the city is even larger

and more massive than we previously thought.

Narrator: Based on tikal's size, tom estimates the city's kings

likely rule over more than 100,000 people.

This makes tikal one of the largest cities ever to exist

in the ancient americas.

Tom's latest lidar results suggest

that an astonishing 60,000 structures

lie buried in the jungles of guatemala.

The mayans build an urban civilization,

just like the people of ancient babylonia or egypt.

But all ancient cities depend on farming

to feed their huge population.

So how does tikal survive?

The lidar data reveals another clue.

Tom discovers unusual linear features

hidden in the heavily forested, swampy ground outside tikal.

Garrison: This doesn't seem to be a natural feature.

And what this makes us wonder is, is this agriculture?

Is this how they're feeding that vast population at tikal?

Narrator: To find answers,

tom must investigate in the field.

G.P.S. Guides him and his team

to the exact spot identified in the lidar scan.

They hack through dense jungle to get to the site.

Garrison: Well, we're here.

I think what we're seeing, all of these little ridges,

these are the subtle features that we must be seeing,

and it goes on for kilometers.

These are gonna be the agricultural fields

of the people of tikal.

Narrator: The ridges suggests

tikal's rulers deforest and drain

the only fertile areas close to the city, the swamps.

They then cut a network of terraces to cultivate crops.

Garrison: And that's what's going to be the lifeblood of the city.

That's what supports this massive population.

And when you have more people, your city has more power,

you have more wealth.

It could be that it's these swampy areas,

where we can hardly see anything,

that are actually the key to understanding tikal.

Narrator: Tikal's population burned the jungle

to clear it of trees

before building the city's terrace system

and planting crops in soil fertilized by the ash.

To get the most out of this precious land,

they grow squash on the ground, maize that rises up through it,

and beans that climb up the corn.

Maze is their most important crop.

As a daily staple,

the maya eat it boiled as gruel or ground into flour

to make tamales and tortillas.

This agricultural land is so vital to the maya

that the maize god is one of their chief deities.

Tikal is an ancient american superpower.

But great cities like this suddenly collapse

1,100 years ago.

What brings the great mayan civilization

in the ancient americas to an end?

And why do people in south america

create an entirely different kind of wonder?

♪

narrator: 1,300 years ago,

the mayan civilization is one of the greatest on the planet.

Millions of people live in dazzling cities like tikal.

They build huge pyramid temples

constructed with simple stone tools.

But today, almost all of it is gone.

♪

rising from the thick jungle...

Tikal's biggest pyramid is a wonder of engineering.

Consisting of seven platforms,

ascended by incredible steep steps,

climbing over 200 feet high

and crowned with a shrine to the gods.

This is the tallest manmade structure

in the ancient americas.

But by the 1500s, it is so completely overgrown,

the first european explorers never even find it.

What happens to this mighty civilization?

Lucero: The classic maya where a complex society.

There's likely not one reason for its demise.

Archeologists have presented many ideas

as to why it happened.

Narrator: Theories range from invasion and famine

to a rebellion against the ruling classes.

Anthropologist lisa lucero thinks a clue

lies with the dazzling pyramids that make tikal special.

It begins with this limestone,

which is found throughout tikal.

First, the maya would burn limestone to create lime,

after which they would add water and let it ferment

before they would add sand to create plaster.

Narrator: The maya spread the plaster over tikal's pavements

and buildings.

They then leave the plaster to dry

and paint it with vivid colors.

But little do the maya realize

achieving the effect consumes vital resources.

Lucero: This stone is about a meter square.

It would take 20 trees to burn enough limestone

to create plaster to cover this one-meter stone.

Imagine what it would take to cover

the monumental buildings of tikal,

some of which are over 70 meters tall and 50 meters wide.

It would take thousands of trees.

Narrator: As tikal grows

and its rulers build larger and larger buildings,

the demand for lime plaster increases

and tikal's inhabitants cut down more and more trees

to burn limestone to make it.

Lucero: Tikal was occupied for nearly a thousand years.

But once kings divert it from a sustainable path

and increasingly became addicted

to building monumental architecture,

they became more vulnerable to any disruptions to the system.

Narrator: Deforestation

unbalances tikal's fragile ecosystem

and magnifies the environmental changes in central america

at that time.

Lucero: There were several prolonged droughts

lasting anywhere from 8 to 13 years.

Between 800 and 900 c.E.

This meant that reservoir levels were dropping.

Crops were decimated.

Fewer farmers came,

and kings increasingly lost power.

Ultimately, people abandon tikal for good.

Narrator: With no water to control,

many mayan rulers lose their hold over the population.

The people leave their cities to find new opportunities.

Dynasties collapse.

And by 950 a.D., tikal is a ghost town.

Lucero: There might have been a remnant population of 100

or so people, but it was never occupied again

to the extent it had been before.

Narrator: As tikal falls,

chichen itza briefly takes its place

as the greatest mayan city, before suffering a similar fate.

But hundreds of miles away in south america,

another civilization, the incas, take a completely different path

and carve out a huge empire.

Why do the incas build the fourth wonder --

mountainous machu picchu?

And what lies inside this lost temple of gold?

♪

narrator: In the 1500s,

the americas are home to two mighty civilizations.

In the north, the aztecs build tenochtitlan,

one of the biggest cities on the planet.

But in south america, a people called the incas rule

one of the largest empires in the world.

The incas live hundreds of years

after the maya and the olmecs.

Like them, they build huge stone wonders

without the technology available in the old world.

But the incas are very different

to their neighbors in mexico or guatemala.

They build a civilization of remarkable originality,

and their crowning jewel

is wonder number 4 -- machu picchu.

Machu picchu's ruins are perched along a perilous ridge

that connects to prominent mountain peaks.

Stone terraces cling to the steep sides,

home to dozens of near pristine buildings.

Almost every single one is made of granite,

one of the toughest rocks on the planet.

Some are so well-made

that they don't even need mortar to hold them together.

Why do the incas build places like machu picchu

instead of pyramids?

What is the purpose of this city in the clouds?

There are many theories from a royal palace to a trading hub.

José bastante is machu picchu's site director.

He believes the answer lies with the buildings themselves

and uncovers evidence that tells a new story.

Most of the things going on in machu picchu

are related to the ceremonial part.

Narrator: Teams of archeologists are investigating

every structure at machu picchu.

They're discovering that many of the buildings here

seem to align with the movements of the sun.

Could machu picchu be linked to the inca religion?

The sun is the most important deity of the incas.

José heads deeper into the city to investigate.

In the center stands a sacred stone known as the intihuatana.

Does this peculiar rock have a religious function?

Today sees one of the most important solar events

in the inca calendar --

the equinox, which marks a change in the seasons.

On most days of the year, the intihuatana stone

and everything around it, including people, cast a shadow.

But on the equinox, as the sun reaches noon,

something strange happens.

♪

the intihuatana stone's shadow disappears.

Is it designed to mark this special day?

Because of the particular shape and angles

of this lithic sculpture

that we call "intihuatana,"

that is actually an altar,

there is no shadow cast during the equinoxes.

Narrator: How do the incas achieve this incredible effect?

All along the equator, on the equinox,

the sun passes directly overhead,

causing shadows on the ground to practically vanish.

But machu picchu is 13 degrees south of the equator

where the sun is not overhead.

So to mark this special day,

the incas sculpt the rock to lean at precisely 13 degrees

so that it points directly at the sun

and its shadow disappears.

Machu picchu seems to be a holy city in the clouds.

A place where the incas can interact

with their most important god, the sun.

♪

some believe that the incas

choose this site, high in the mountains,

to get a better view of the sky.

It's a tempting theory, but there's a problem.

Machu picchu is regularly shrouded in cloud.

So why build a temple complex to the sun here?

José believes a new discovery helps to explain

why the incas built a solar observatory

in such a challenging environment.

This huge rocky outcrop that resembles a mountain.

Is a shrine.

Narrator: For decades,

archeologists think this is just another inca temple.

What they didn't realize is that there was something else

over here that they didn't notice

and we have just found.

Narrator: José uncovers faded artwork,

hiding in plain sight.

Bastante: What we're seeing is traditionally called rock art.

But in the andes, this is a quilca.

Narrator: José thinks that this rock art

is not made by the incas.

It looks centuries older.

Bastante: These graphic motifs have no relationship whatsoever

with the inca civilization during 15th and 16th century.

Narrator: Machu picchu mountain may have been sacred

for thousands of years, long before the incas arrive.

This is an evidence of presence

of pre-inca people in the area.

We are talking about between 800 to 1200 a.D.

Narrator: Archeologists believe this mysterious painting reveals

why the incas are drawn to this remote site.

Bastante: What we're proposing

is that this place was considered as sacred

even before the incas.

The incas just arrived

and realized the sacredness of the place.

Narrator: José believes machu picchu is built here

because it is already a sacred site

with an ancient connection to the gods.

Machu picchu is a miracle of engineering and devotion,

a sacred mountain metropolis worthy of the sun god.

Civilizations on both sides of the world worship the sun.

The incas, like the egyptians

who build the great pyramid of giza,

believe their rulers are descended from a solar deity.

But it is just one of many astonishing cities

in their vast empire.

How does this civilization create all these buildings

in less than a hundred years?

We'll unearth the answer in the next wonder --

a lost city of gold.

And could new discoveries in southern peru

finally reveal the secrets of the bizarre nazca lines?

♪

narrator: The seven wonders of the ancient americas

are engineering masterpieces.

Huge monuments built using only simple stone tools.

In the 15th century, the incas take the wonders to new heights.

They construct entire cities like machu picchu

in less than a century.

Today, this mountain metropolis is regarded

as one of the world's greatest treasures.

But in the time of the incas, one building is even greater.

The fifth wonder -- the temple of the sun, cusco.

500 years ago,

this temple is the most magnificent megastructure

in south america.

Outside, a field of maze made of real gold

and life-sized golden statues of llamas.

Inside the sanctuary, buildings gleam like beacons.

Their thatched roofs woven with gold threads

and their walls plated with solid gold.

In the hall of the sun hangs a huge golden disc...

...Where only the emperor is allowed to sit.

This golden temple is very different

to the pyramids of mexico.

It sits at the center of four inca highways

which connect to all four corners of their vast empire.

Smaller versions of it exist in many inca towns.

Cusco is the rome or alexandria of south america.

How do a people with no modern weapons,

or even the wheel, build the largest empire

ever seen in the americas?

Archeologist roxana gómez torres

investigates a burial ground 300 miles north at bellavista.

It belongs to a tribe called the ichma.

New discoveries here

are transforming our view of the incas

and how they expand their empire.

Roxana and her team are unearthing mummies.

[ speaking spanish ]

narrator: The incas, like the ancient egyptians,

mummify and preserve the bodies of their rulers.

In egypt, royal mummies

are hidden away to resurrect them in the afterlife.

But in peru, they are kept inside

the temple of the sun in cusco

and even taken out for special religious festivals.

Roxana brings the mummies.

She's discovered to the laboratory for analysis.

This one is almost six feet in length,

the outside preserved in near-perfect condition.

Its huge size suggests that it contains the body

of a particularly well-respected person.

The mummy appears to be that of an ichma noble.

But it's covered from head to toe

in high-quality, inca-designed fabrics.

The mummy also has a false head

to give it a more human shape.

It's a feature found on high-class mummies.

This ichma aristocrat

is buried almost exactly like an inca.

Why?

X-rays reveal further signs of inca influence --

small copper implements.

Domestic items from tweezers to metal hairpins

and the thorns of colorful seashells

are the kind of valuable items

that would normally only be buried with important people.

Roxana thinks that this local chief

is given these burial goods by his inca overlords.

These gifts reveal

that this important person is an inca ally.

By showering him with precious objects,

the incas buy his loyalty.

Roxana believes that this might explain how the incas

rise to power.

Alliances allow the incas to construct cities

like machu picchu and build a vast empire

that stretches 2,000 miles across south america.

But not everyone wants

to join this new south american empire.

Those who resist are crushed with brutal force.

The incas are fierce warriors.

Thanks to their allied troops,

they are able to field vast armies,

reportedly up to a quarter of a million strong.

Inca armies intimidate their enemies

with a terrifying show of force as they expand their empire.

[ men ululating ]

before a battle, the inca king offers his opponents

a chance to surrender,

as long as they agree to pay a regular tribute.

If they refuse, inca soldiers armed with stone missiles

unleash a carefully timed barrage of deadly rocks.

Then inca shock troops armed with maces and clubs

go in to finish off the enemy in close combat.

The incas win a vast empire through bribery and brutality.

They export their way of life

and their style of architecture across the andes.

But there is one wonder in their vast empire

that predates them by almost a thousand years

and continues to baffle investigators --

the nazca lines, giant animal shapes and geometric spirals

that some believe must be extra terrestrial in origin.

Could new discoveries reveal the true purpose

of the nazca lines?

And why did the people of easter island

build hundreds of giant stone statues

in one of the most remote places on earth?

Narrator: Hundreds of years ago,

civilizations like the inca and the maya

create astonishing wonders across the americas.

Many of their pyramids and statues are similar

to the original seven wonders of the ancient world.

But the sixth wonder of the ancient americas

is unlike anything else on the planet --

the mysterious nazca lines in peru.

These ancient images that only makes sense from the air.

There's outlandish theories about the nazca lines,

including ancient hot-air balloons, ancient aliens,

a racetrack.

And I think the reason

why we keep having these ideas come up

is that the lines remain an enigma.

Narrator: The lines are hundreds of alien-looking drawings made

by a people called the nazca, some over 2,000 years old.

Geometric shapes that stretch across entire landscapes.

Arrow-straight lines that crisscross through the sand

for hundreds of miles.

Detailed images --

dozens of them stretching hundreds of feet across.

♪

how do ancient people create these mysterious monuments?

And why?

Archeologists discovered the nazca

make the lines by moving stones

and allowing those underneath to bleach in the sun.

From the air, it creates the effect of a drawing

we call a geoglyph.

Today, they repair the damage done by centuries of rock fall,

remove stray stones, and uncover new images like this one,

a hunting killer whale.

But how did the nazca supersized their designs

when they have no way of seeing them from the air?

Some believe that they use ancient hot-air balloons,

or even more extraordinarily,

have help from extraterrestrial visitors.

But any explanation must account

for some curious inconsistencies in the designs.

One geoglyph, called the spider, is pure symmetry,

its abdomen is a near perfect circle

and its limbs are precisely mirrored parallel lines.

Right next to it is the condor.

It's just as complex with razor-sharp connecting lines.

But it contains curious mistakes.

The wings aren't the same size,

one claw is bigger than the other.

Could these errors be a clue to how the nazca build the lines?

♪

archeologists christy conlee and johny isla

investigate how the lines are made.

They've come to the edge of the desert to experiment.

Many of the nazca lines are incredibly long.

Some stretch for miles.

And then pace out about 10 meters.

Okay.

Narrator: The first thing

christy and johny want to work out

is how the nazca make straight lines with basic equipment.

First, they put two stakes in the ground

at a distance from each other.

Yeah, that looks good.

The next task is to put in a third steak

that lines up with the first two.

It's done by eye, creating a sight line

a little bit to the left.

Perfect.

This can be repeated any number of times.

Okay, next.

Finally, christy and johny use rope

to create a precise line guide between the stakes.

They could have done this in the past with materials

they had, cotton or llama, fiber, yarn, or cordage,

and they could have used rocks as a hammer

and wooden stakes.

But many of the nazca lines are more complex

than a simple straight line.

How were these made?

One theory is that they use an ingenious technique

to upscale the images.

They start with a small drawing on a piece of cloth.

Then they divide it with a grid...

...And draw a huge grid on the desert floor,

copying each cell,

carving the design into the earth.

Once they dig the lines into the ground,

they wipe away the grid and have a perfect nazca line.

But in this technique, errors mainly show up in single boxes,

which does not explain the asymmetry in the condor.

Christy believes she can use a coordinate system,

rather than a grid, to explain the asymmetry in the lines.

Okay, well, let's do an experiment.

Let's try and make our own geoglyph.

So I sketched out a somewhat simple one, a star,

and we can try, and you can do one side and I'll do the other

and see if we can make symmetrical image.

A coordinate system involves working out the distance

of key points on the design from the central dissecting line

and then scaling up these distances

conlee: And we'll pace down 5 1/2 pieces to here

and then over to our first points of the star,

and we'll continue from there.

Let's give it a try.

Johny and christy do not have identical strides.

Will this introduce some asymmetry into their star?

They move on to higher ground to see their work from above.

Conlee: So from up here, it doesn't look really distorted.

I mean, I can see a little bit on my side to the right

is maybe smaller, but it's -- I think it looks good.

The star is not bad, but it's not perfect.

The difference in pacing explains the apparent errors

in some of the nazca lines.

But why do the nazca stamp their artworks

onto these desert hills?

No other civilization in the world

creates a wonder quite like this.

Could the answer lie with these mysterious pyramids

in the valley below?

And...

Why did the people of easter island

create the final wonder of the ancient americas --

hundreds of gigantic stone heads?

♪

narrator: The seven wonders of the ancient americas

are remarkable engineering achievements,

huge sophisticated monuments built by civilizations

using little more than stone tools and human strength.

But the nazca lines, the sixth wonder,

are so strange and baffling.

They continue to defy explanation.

Why do people create huge images

that they cannot see from the air

thousands of years before the invention of air travel?

The lines are unlike anything in the new world or the old,

but a clue lies with some familiar monuments,

mysterious pyramids that rise up

in the nearby valley of cahuachi.

Blowing away the walls at cahuachi

reveals hidden cavities.

Inside them, archeologists find rich offerings,

giant seeds stuffed with rodent head sacrifices,

a human skull cradling a guinea pig carcass,

and mummified human trophy heads --

the ultimate gift to the gods.

Scattered around them are shards of pottery.

They depict animals, just like many of the nazca lines.

Could offerings like these reveal why the nazca

create their images in the peruvian desert?

The first step is to find out if the same people

who build the pyramids also make the nazca lines.

Artifacts at the regional museum of ica

match those found at the pyramids of cahuachi.

Conlee: Oh, wow.

Narrator: Christy conlee examines the pieces.

This is really a fantastic textile.

Narrator: The fabric survives for more than 1,500 years.

We're here in the desert and there is no water,

there's no rain.

And so these organic materials do not rot.

Narrator: Some of the imagery is instantly recognizable.

What you have here are a series of hummingbirds.

You have these beaks of the hummingbirds

that are going into these, like, amazingly constructed flowers.

And just one after another.

The symbolism is so reminiscent of the hummingbird geoglyph.

Narrator: The textiles are just as revealing as the ceramics.

Conlee: So we have a monkey. This spiral pot.

And this is an amazing example of an orca, of a killer whale.

There's actually blood being represented here in its mouth,

its tail.

Narrator: The orca has curious motifs

of heads that it has swallowed.

Conlee: For me,

there's absolutely no doubt that the same culture

that made this pottery also made the geoglyph.

Narrator: The same images from the desert

appear again and again.

The similarity of the spiral of the bowl

and the spiral geoglyph.

The monkey with its curling tail,

its jug ears, and the hands that reach around and clasp together.

The orca, with its jaws,

its round eyes, and its distinctive tail,

even down to the symbolism of a swallowed head.

Radiocarbon dating confirms that the pottery

and most of the lines are made by the same nazca people

who live here thousands of years ago.

♪

archeologists also find pieces

of smashed nazca pottery at many of the lines.

It suggests that people carry out religious rituals here,

just as they do at cahuachi.

Could these broken offerings at last reveal

why the nazca make the lines?

Archeologist johny isla

believes the way to understand the lines

is not to view them from above, but to look at them as the nazca

would have seen them at ground level.

[ speaking spanish ]

♪

narrator: Johny has spent countless months

up on the plateau documenting

and restoring newly discovered nazca lines.

It's given him a unique insight.

Many are made up of a single unbroken line,

like a maze with a way in and a way out.

Johny believes that these lines are pathways.

If he's right,

the nazca lines are not to be viewed as giant pieces of art,

but processional pathways.

♪

johny's exciting insight reveals the nazca lines

in a radical new light.

The nazca people use the lines

as giant outdoor temples.

They walk along them,

leaving pots containing offerings to the gods.

The nazca invent a unique civilization

that is as imaginative as that of the maya and the incas,

the babylonians and the egyptians.

Archeologists are finally beginning

to crack the nazca code.

But the mystery surrounding the final wonder

are even harder to decipher --

the giant stone statues of easter island.

Why did the people of this tiny island build such massive icons?

And why do so many wonders in the ancient americas

disappear for hundreds of years?

♪

♪

narrator: Easter island

is one of the most isolated places in the world.

A solitary outpost of volcanic rock

lost in the vast pacific ocean.

Today, the island is part of chile in south america.

It is also home to one of the most

mysterious wonders on earth -- the moai.

All along the island's coast, wearing solemn expressions

and top knots of shaped red stone...

♪

...Moai statues stare inland from deep eye sockets.

On their backs are mysterious faded carvings.

They stand on a solid platform made of precisely cut blocks.

But under them lie grisly secrets.

♪

why do the people here create these wonders?

The moai are the lasting legacy of a people

who arrive on easter island over 1,000 years ago

called the rapa nui.

They build a civilization in total isolation

and leave behind very little about their lives.

Anthropologist mara mulrooney thinks that the first step

towards discovering the meaning of the moai

is to find out just how important they are

to the people who build them --

the first rapa nui.

She's on her way to the remains of a village

in the island's northwest.

It's always exciting for me to be able to survey areas

that I haven't surveyed before.

The rapa nui once lived in villages near the coast.

Each tribe has its own set of magnificent moai statues.

But by contrast, their houses are simple structures.

I don't know. What do you think?

I mean, maybe those were sort of like a front terrace

of reused paenga stones.

Yeah, we got some paenga.

Yeah, yeah.

This isn't a foundation or a... [ speaks native language ]

or a boat-shaped house.

Which would have had a super structure

consisting of twigs and grass.

It would've looked very much like an overturned boat.

Narrator: Why do a people who live in modest houses

made partly of twigs and grass

carve such colossal stone monoliths?

The moai stand on huge ceremonial platforms called ahu,

built from pebbles and basalt slabs.

But buried deep beneath many of them,

investigators unearth macabre clues

to the makers of the moai, mysterious chambers

filled with human bones.

At one ahu, archeologists uncovered the remains

of over 100 individuals.

Almost every skeleton has a deformed kneecap.

This suggests they are probably all related.

Why are so many members of the same family

buried below the statues?

And can this reveal the reason they are built?

Mara examines the houses next to this collapsed platform.

She thinks there may be a connection

between these buildings and the moai.

These houses are arranged sort of

in a semicircular pattern

around the principal ceremonial site,

or the ahu, which is located right over there.

It's about 200 meters away.

Narrator: This is the largest boathouse

found anywhere on easter island.

Its size means it probably belongs to a chief.

Mulrooney: This was truly something special.

When the high chiefs, or the ariki,

would have woken up and walked outside their door,

they would have seen the moai.

Narrator: Mara's investigations reveal that the largest houses

are clustered at the base of the moai.

This suggests that the more important people

are in rapa nui society

the closer they live to the monuments.

Mulrooney: These boat-shaped houses were concentrated

around the focal point of the ahu.

And further inland,

what we see are smaller houses, houses of commoners.

Narrator: Mara thinks that each statue

symbolizes a long-dead ancestor

such as a chief.

Mulrooney: The moai are very closely connected

with the people who live here, and they're specific

to their communities.

Narrator: The moai why are a direct link to these ancestors

and considered to be an important part of the community.

♪

the first people who arrive on easter island

split into tribes and divide the land up between them.

They soon begin constructing moai,

with each growing clan building statues to honor

their own ancestors.

Over time,

the number of statues increases, growing with the population.

Moai building likely becomes a competition as each tribe

tries to outdo the other with bigger and better statues.

Mulrooney: Just as you

would want to impress your neighbors,

so, too, did the rapa nui.

And so there was a lot of friendly competition.

The monumental size of a structure

really reflects the success of its community.

Narrator: The moai are at the heart of island life,

a direct link to the past.

The people on this remote island have few natural resources.

But the same creative spark

that inspires the olmec to carve giant heads

or the ancient greeks

to build the mausoleum of halicarnassus

also exists within their civilization.

But here on this platform,

the statues are lying on their faces.

The islanders pulled down the moai

after europeans arrive, bringing death and disease.

How does contact with the world

of the original seven wonders

transform the americas and their wonders?

And do more wonders remain hidden,

waiting to be discovered?

♪

♪

narrator: The seven wonders of the ancient americas

are among the most extraordinary structures in history.

Their sheer size, sophistication, and beauty

equals the wonders of ancient egypt, babylon, and greece.

The huge differences in technology confirm

that both sides of the world have no contact with each other.

Archeologists are not even sure

how much communication there is

between the civilizations of central and south america.

Despite this, they all build strikingly similar creations,

shaped by the tools they use and the environments they live in.

But almost all of the american wonders

lie forgotten by the wider world for centuries.

By contrast, the fame of the traditional seven

persists throughout the centuries.

Why does all knowledge of these remarkable

american structures vanish

along with the civilizations that build them?

A clue lies in the inca capital, cusco.

From the outside, the convent of santo domingo

looks like any other christian church,

a colonial sanctuary built in the shape of a cross.

But for nearly 500 years, it has hidden a secret.

Spanish invaders, conquistadors, build this church

over the masterful masonry of the incas'

most holy sanctuary, the temple of the sun.

Outside, only the original retaining wall is still visible.

Placing a christian building over a sacred inca sites

is one way that europeans stamp out the inca religion.

It is a story repeated across the americas.

In a bitter twist of fate, the european civilizations

that preserve the memory of the original seven wonders

almost erase those in the new world.

In mexico,

european conquerors wipe out the aztec empire.

They destroy the great pyramid of tenochtitlan,

the templo mayor.

Today all that remains

lies buried underneath mexico city.

The inca never reveal the location of machu picchu

to the spanish, who conquer their empire.

But the fate of this metropolis

also raises an extraordinary possibility --

are there more wonders waiting to be found in the americas?

At machu picchu, archeologist josé bastante is convinced

that we know only a fraction of what surrounds this city.

He thinks evidence of a lost road network

could still exist today.

We're still discovering new inca roads

within the sanctuary borders.

Narrator: To find these roads,

josé looks for unusual entrances

around the edges of machu picchu

that don't appear to lead anywhere, like this staircase.

Bastante: This staircase was always a mystery.

We didn't know, really, where it was coming from.

But recently we just figured it out.

We found the road.

The only issue is that the road has collapsed at certain points,

so we cannot follow it completely.

[ conversing in spanish ]

♪

narrator: José's team

is investigating a newly discovered trail.

He believes this is the first time this road

has been explored. For centuries.

Bastante: Next to machu picchu city,

we have probably found all the roads,

but in the area,

there are still many roads

to be found lost in the vegetation.

Narrator: So far, archeologists

have uncovered a web of eight roads

leading into machu picchu.

In the future, josé plans to use aerial scanning technology,

lidar, to strip away the forests and search for more.

He hopes it will reveal new lost wonders of the americas.

Technology is opening up a new age of exploration

in the americas,

rediscovering temples, pyramids, and lost cities.

But what archeologists have discovered so far

about the people who build them

already tells a remarkable story.

The seven wonders of the ancient americas

reveal how civilizations living on opposite sides of the world,

with no knowledge of each other,

can create remarkably similar-looking megastructures.

Pyramids, larger-than-life statues,

and dazzling cities.

Each one of these monuments is shaped

by the societies that built them

and the technology available to them.

But the builders of the original seven wonders

and those in the americas share a common trait.

They all use whatever resources they have

to overcome huge challenges and realize their dreams.

The seven wonders of the ancient americas,

just like the original wonders of the ancient world,

are a testament to human ingenuity and ambition.

♪

♪

♪

♪