All language subtitles for Ancient.Engineering.S01E03.Secrets.Of.The.Pyramids.1080p.AMZN.WEB-DL.DDP2.0.H.264-NPMS_track3_[eng]

- [Narrator] We are surrounded

by extraordinary
feats of engineering,

constantly pushing the
boundaries of what's possible.

- Without engineering,
there'd be no modern world.

- [Narrator] Gigantic cities.

Amazing infrastructure.

And ingenious inventions.

- Engineering is the key to
turn dreams into reality.

- To reach these
dizzying heights

today's technology
relies on breakthroughs

made by ancient engineers.

- It's mind boggling
how they did this.

- [Narrator] How did
early civilizations

build on such a scale?

- They raised the bar
for construction in a way

that no one thought possible.

- The sheer engineering ability

is in itself impressive.

- [Narrator] By defying
the known laws of physics

and daring to dream big.

They constructed
wonders of the world

from gigantic pyramids,

to awe inspiring temples

and mighty fortresses.

All with the simplest of tools.

- Can you imagine the skills

people would have needed
to build like this?

- [Narrator] Now it's possible
to unearth the secrets

of the first engineers.

- They managed to
construct edifices

that has survived
the ravages of time.

- [Narrator] And
reveal how their genius

laid the foundations for
everything we build today.

[awe-inspiring music]

Humanity is obsessed
with surpassing

the limits of construction
and engineering.

Establishing new records only
to break them again and again.

- As humans we always
want to advance,

as engineers, always want
to push the boundaries.

- [Narrator] Every decade
sees radical new structures.

And bigger is always better.

rising a dizzying half
a mile above the desert,

Dubai's Burj Khalifa
currently reigns

as the tallest
structure in the world.

Wrapped in a glass curtain wall,

the supertower's
sleek silhouette

dwarves the surrounding city.

And in Ontario,
the Absolute Towers

appear to shimmer and twist
around their own axes.

With continuous balconies
and elliptical floor plans,

the skyscrapers take on shapes

that seem to defy
the laws of physics,

But these architectural
monuments also
express the wealth

and power of those
who commissioned them.

- They are expensive and
they're always symbols of power

to a certain extent.

- [Narrator] Engineering as
the ultimate status symbol.

- They want to build the
biggest thing they can do

to make a point of
saying I was here.

- Creating massive eye
catching structures

is one of the best
ways to impress.

Whether they're
captivating onlookers

or symbolizing the
might of a nation,

these statement buildings
are found across the globe

reaching ever higher.

- We certainly see
it going on today,

the race to be the tallest
building in the world.

But while modern tall buildings

are usurped by a new
rival every few years,

in the ancient world,
one civilization

built a structure that
would reign supreme

for almost four millennia.

And it emerged in ancient Egypt.

- In terms of building
big, tall, structures

I don't think anyone
rivaled the Egyptians.

- What the Egyptians did
was take monumental building

to its extremes.

- [Narrator] Egypt's
most iconic structure

became the tallest
building in the world,

a title it retained for
more than 3,500 years.

The Great Pyramid of Giza,

the largest pyramid ever built.

Last of the original

seven Wonders of the
World still standing.

- It was recognized by the
ancient world as extraordinary,

and it's still an
iconic symbol of Egypt

and of the ancient
Egyptians today.

- [Narrator] At a time
when most buildings

were only one story high,

the Egyptians created
something unimaginable.

Soaring to over 475 feet,

the pyramid remained the
world's tallest structure

until the 14th century.

- It's the biggest ancient
building of them all,

it's still standing
and it's a real icon.

- [Narrator] But the great
pyramid isn't only about scale.

With principles that
still apply today,

it's also a masterpiece
of mathematics

and precision engineering.

Aligned to face true north
with pinpoint accuracy.

- The size makes it impressive,

but it's also the dimensions,
the proportionality.

The measurements
are very accurate.

Each side is equal.

- [Narrator] Built with
over 2 million stone blocks.

- Some seemed to weigh as
much as two and a half tons.

And these fits together
like a jigsaw puzzle.

The expertise that went

into making this
thing was incredible.

- [Narrator] It's a triumph
against impossible odds.

Believed to have been
constructed in just 20 years,

the result of extraordinary
human ingenuity.

- It's built in such a
carefully engineered way

that it seems impermeable
to the passage of time.

It's a solid structure
built on solid foundations,

built to last,
which indeed it has.

- [Narrator] The great pyramid

is an ancient
engineering masterpiece,

but this world famous monument
is still shrouded in mystery.

For centuries it has remained

one of the great
engineering enigmas.

- The complex engineering
that went into that

without the modern
day technology

that we have is
really astounding.

The kind of challenges just to
build something of that scale

with the materials
they had available

is really an amazing
feat of engineering.

- [Narrator] What
drove the Egyptians

to erect such enduring
monuments in the first place?

- Of course, there
are many theories

as to why the pyramids were

constructed by the
ancient Egyptians.

- [Narrator] Were they
really enormous burial places

with hidden chambers inside?

Or did they serve
another function?

- Even the ancient Egyptians
looked back generations later

at this thing, with
some degree of mystery.

- [Narrator] To find
answers, we need to go back

to the first pyramids.

Over 5,000 years ago,

Egyptian civilization
began to emerge

along the banks of one of
the world's longest rivers,

the Nile.

- For the ancient Egyptians

the Nile was fundamental
to their entire culture.

Without the Nile
there is no Egypt.

- [Narrator] Annual floods
brought nutrient rich waters

to the lands along
the Nile's banks,

giving life and fertility.

- It's that that could support
this great civilization

and allow it to store grain
and grow and grow and grow

and do more and more
remarkable things.

- [Narrator] For the most
part, it was a blessing

and Egypt became
a land of plenty,

but during times of drought,
there was starvation and death.

- If the Nile flood was too
low, then famine would follow.

If the Nile flood was too high,

then entire villages
could be washed away.

- [Narrator] This
precarious existence

led to an obsession with
death and the afterlife.

And in order to protect
the bodies of their dead,

the Egyptians developed a method
of artificial preservation,

mummification.

- Mummification was
invented to provide

a permanent physical
home for the soul,

which could wander
around, live forever

and then come back at
will into its body.

- [Narrator] The
body of the deceased

was washed and purified.

All the organs were removed,
excluding the heart.

It was then dried out with salts

and wrapped head to toe

before finally
being laid to rest.

- Some bodies were
simply wrapped in linen

and put in the desert.

- [Narrator] The desert sands
may have been good enough

for ordinary Egyptians,

but they're mummified rulers

demanded a more
secure resting place.

- The ancient Egyptian king
was essentially worshiped

as a kind of god in life,

and certainly as a
god in the afterlife.

- Workers used
simple hand tools,

excavating huge underground
burial chambers for their kings,

protective tombs for their
journey into the afterlife.

And mummification continued
for thousands of years,

but other techniques
for preserving

the human body after death
have since been invented,

including one very
recent innovation.

Hundreds worldwide have
had their corpses frozen

in special cryogenic chambers,

preserving their remains in
the hope that resurrection

may be possible in the future.

- People hope that
when they're eventually

brought back to life,

that there will have
been advances in medicine

that means there'll be able
to treat incurable diseases

that we have today.

- [Narrator] The procedure
must begin minutes after death.

Antifreeze compounds
replace the corpse's blood

to prevent harmful
ice crystals forming

as the body is slowly
cooled to a temperature

of minus 320 degrees Fahrenheit,

and finally lowered into
a tank of liquid nitrogen

where it remains ready
for the afterlife.

But over 4,000 years ago,

all the ancient Egyptians had
was their belief in the king.

And they were certain the
efforts their engineers made

to preserve the royal
body would be rewarded.

- Each royal mummy
had to be buried

in a very, very safe place.

And it was only
when this was done

could Egypt truly thrive
because it was believed

that each successive Pharaoh
contained divine power.

- By creating a secure
burial chamber for the King,

the people believed
that the survival

of their civilization
was insured.

So royal grave sites became
unmissable monuments.

- The earliest
Kings were buried in

what we call mastaba tombs,

low rectangular structures
with sloping sides.

They can be quite large, but
they weren't made from stone.

These were made from mud brick,

- Mud brick was the most common
building material in Egypt

because simply it's
made of the mud

from the banks of the Nile.

- [Narrator] But a
belief in the afterlife,

wasn't the only motivation
for tomb building.

Each successive ruler wanted

a memorial larger and
grander than the last.

Royal tombs had become
a mark of status.

Then around 2650 BC,

one genius of ancient
engineering had an outlandish,

world-changing idea to take
tomb building to new heights.

- King Djoser had
his architect Imhotep

embellish his
simple mastaba tomb.

- You can see the really big
leap from the previous phase.

This huge leap that
Imhotep seems to make.

- [Narrator] One
that would change

the Egyptian landscape forever.

Imhotep wanted something
grander to commemorate his king

and took Egyptian engineering
to the next level, literally.

He envisioned six
different layers of mastaba

stacked on top of each other,

but this new design would
involve a tremendous amount

of material and weight.

So a radical
breakthrough was needed.

- The great leap forward

was that the Djoser's pyramid

was built of limestone
rather than mud brick.

- The use of stone
revolutionized
construction in Egypt.

- The architect Imhotep
also changed the design,

instead of the
rectangular mastaba,

it was made into a square,

which is effectively
far more stable.

- [Narrator] Imhotep had
designed Egypt's first pyramid.

It would prove a
massive undertaking.

- Building with
stone is not easy.

It's not cheap, it
takes a long time.

It's not an easy
material to work with.

- [Narrator] Over the course

of Djoser's nearly
20-year reign.

His builders assembled the six
stone layers of his pyramid,

a colossal structure,

unlike anything the Egyptians
had ever laid eyes on.

- Djoser's pyramid is probably

the world's first monumental
building in stone.

- [Narrator] This engineering
masterpiece reinforced

the king status as a living god.

196 feet tall, the
groundbreaking form

would come to be known
as a step pyramid.

- It can only be imagined

what impact first
pyramid must have had

on the Egyptian population.

The whole structure was designed

to be seen from
the valley below.

- [Narrator] Imhotep
would go down in history

as the world's first engineer
and architect known by name.

He had created the
original skyscraper.

Some modern architects have
also become household names,

world famous, thanks to
their unique designs.

One of the greatest in
their ranks is Frank Gehry.

His buildings are
monumental works of art.

- He has such a
signature style to him

that you can pretty
much look at a building

and probably guess correctly
that that that's a Gehry.

- [Narrator] Cutting
edge technology

helps deliver the
engineering solutions

that bring Gehry's
sculptural sketches to life.

- For me it's about
his use of geometry

to create really,
really unusual shapes.

- In a sense he was a
bit like the Egyptians

who built the pyramids as
they were making things

that would make people
go, wow, look at that.

- [Narrator] New forms
never seen before.

Making headlines
around the world.

Gehry is an architect who
refuses to accept limits,

something he and Imhotep
appear to have in common.

But why was the
step pyramid design

chosen for Djoser's tomb?

Some believe that
the pyramid sides

act as a celestial staircase,

guiding the Pharaoh's
soul to the afterlife.

Or could Imhotep have had
a more practical reason?

- If one looks at
the grains of sand

trickling through an hourglass,

they naturally form
a pyramidal shape.

And that's because the pyramid
is a deeply stable structure.

- [Narrator] And a stable
structure is a strong structure.

- A pyramid is very stable
because of having a large base

compared to its height.

You've got basically a
very low center of gravity.

- It's a structure that as
long as you expand the base

can grow infinitely
large because the base

will sustain the structure
as far as you want.

- [Narrator] Their
stable form explains

why the pyramids of Egypt
are still standing tall,

enduring weather and
erosion over millennia.

Djoser's step pyramid launched
an engineering arms race

that would continue
for centuries.

- After Djoser,
the pyramid became

the kind of
stereotypical monument

in which a king would be buried.

They were really showing
off the might and power

of the Egyptian
empire at the time.

We do the same thing today.

People build taller and taller.

- [Narrator] But as with
everything in the modern world,

even big buildings need to be
put up as quickly as possible.

In New York city,

marvels of engineering
continue to be developed.

High profile skyscrapers,

many of which reach
1000 feet tall

with more and more
commissioned each year,

the scale of this new wave of
construction is unprecedented.

And thanks to modern
materials and techniques,

each building can be
completed within a few years.

In ancient Egypt

pyramids couldn't possibly
be built this fast,

but the pressure was on.

Not only to be ready for
the death of the Pharaoh,

but to go taller than before.

- There was this real desire

to exceed what your
predecessor had done.

There is a kind of mark of
your status, of your ability.

- [Narrator] Pushing pyramid
construction to the next level

called for new architectural
and engineering skills.

- Djoser's successors
must have seen Djoser

as a very hard act to follow.

Most of them had
very short reigns

and of course you
can't achieve much

if you're only on the throne
for two or three years.

- [Narrator] In fact, for
the next several decades,

not a single pyramid
was built successfully

until one Pharaoh changed
ancient engineering forever.

In the fourth dynasty
of ancient Egypt,

King Sneferu was determined
to build a pyramid

far larger than
his predecessors.

Blinded by ambition, his
monument was destined

to meet with terrible disaster.

Sneferu began constructing
the pyramid of Meidum,

a step pyramid similar in
design to the original,

but significantly taller.

But halfway through
construction,

the step design was
mysteriously abandoned.

- It seems that the king had
a desire to smooth the sides,

to create a true pyramid.

The King asked that his
workers fill in the steps

with limestone and then apply
smooth casing to the outside.

- [Narrator] It was a
revolutionary concept,

but something went
terribly wrong.

Modern archeology has revealed

that the outer layer of
limestone rested on sand

rather than solid rock.

It put the basis of the four
external supporting walls

under enormous pressure.

Something had to give.

- Unfortunately at some point,
probably during construction,

these sides began
to crumble away.

- [Narrator] As if an
anticipation of defeat,

the king had already
begun construction
on his next pyramid.

- It's a much larger
construction than
the previous pyramid.

And that's going to come with
a whole bunch of challenges.

- [Narrator] But as his
new pyramid grew skyward,

Sneferu found
himself once again,

on the brink of disaster and
construction ground to a halt.

- They might have thought
that the amount of stone

that was gonna be needed
to complete this thing

and the height that
it was gonna to get to

was just gonna be too much.

- [Narrator] Without a
drastic design change

the pyramid couldn't
be completed.

Determined not to
disappoint their king,

Sneferu's engineers changed
the angle of the upper section

from the original 54 degrees
to a much shallower 43,

a modification that would
significantly reduce the volume

and weight of the
pyramids upper half.

The compromise worked,
but it came at a cost.

In saving the structure,
the engineers produced

the strange, comical
shape in evidence today.

It's gone down in history
as the bent pyramid.

Last minute modifications

are still commonplace
in construction.

Most are only minor,

though there are exceptions.

In 1971, the John
Hancock tower in Boston

was mid-construction when
something unexpected happened.

[glass cracks]

Glass began smashing
onto the streets below.

[people shout]

To the engineer's horror,

the reflective windows were
falling out of the building.

- There was too much
movement taking place.

And so the stresses in the glass

were causing these
windows to break

and actually pop
out of the building.

- [Narrator] Over
10,000 window panes

had to be replaced with
heat-treated panels.

This new glass had to be
processed through a furnace

to significantly
increase its strength,

providing greater
resistance to thermal

and mechanical stresses.

But replacing the old windows
was a long and costly process.

- This is one of the challenges

of these prominent buildings.

They're in the public eye as
they're being constructed.

And so any mistakes that happen

are very public and
very embarrassing.

- [Narrator] Before the new
panels could be installed,

the empty frames were covered
up with sheets of plywood,

earning the tower the
nickname, Plywood Palace.

Errors like this
are hard to ignore.

And despite reaching
over 220 feet tall,

Sneferu appears to have seen
his bent pyramid as a failure,

but the King and his engineers
learned from their mistakes

and moved on to a third attempt.

They now knew that large
high-quality blocks of limestone

would strengthen a
pyramid's foundation

and a wider base with a
shallower angle of incline

would increase its stability.

- It is 43 degrees,

like the top part of the
bent pyramid from the base.

So it's a very low lying period.

- After decades long attempts,

Sneferu had finally achieved
the perfect pyramid form.

Engineering genius had
triumphed against all odds,

creating the first
success of a new breed,

the Red Pyramid.

- It's what you call
a perfect pyramid.

The one that conforms

to what we think of
as a pyramid the most.

- [Narrator] The smooth
and symmetrical shape

recognized worldwide.

And at 229 feet tall
Sneferu's monument

would be a tough act to follow.

But this remarkable structure

didn't Mark the Zenith
of pyramid building.

Sneferu's son, Khufu would in
turn dream the unimaginable,

determined to be remembered

as one of Egypt's
greatest rulers.

In the 26th century BC,

one of his first
decisions as Pharaoh

was to commission
his own grand tomb.

This was intended
to be a new pyramid

on a totally different scale.

- There was an
element of wanting

to build bigger and
better than his father.

It was down to him to excel
the king that went before.

- [Narrator] Could
it even be done?

Planned to cover an
area more than 12 acres,

Khufu's pyramid would require

more than 2 million
stone blocks to complete,

adding up to a total of six
and a half million tons.

More than 17 times the weight
of the Empire State Building.

And accuracy of
form and measurement

were of paramount importance
to Khufu's architects.

- One small error at the base

would lead to a complete
disaster closer up to the top,

so the alignment and accuracy

of placing every single block
as they went was critical.

- [Narrator] Creating such
a monumental masterpiece

would demand tens of
thousands of workers.

But would Khufu's great pyramid

be built by an army of
slaves or willing laborers?

For years, controversy raged.

Then in 2010, mud brick tombs

were discovered near
the great pyramid

more than 4,000 years old.

These shafts contain the
skeletons of pyramid builders,

well-preserved by the dry sand,

along with clues to how the
workers were treated in life.

- They were provided with
food for the next world.

They were provided with
the cans of beer and bread

that they'd enjoyed
in this world.

And some of the tombs even
have inscriptions on them

telling us who was buried
inside, what job they did.

- [Narrator] The tombs
provide strong evidence

that the great pyramid was built

by skilled construction workers,

highly regarded for their craft,

not a disposable
workforce of slaves.

They may have been
willing workers,

but a monumental
job still lay ahead.

- To build something
like the pyramids,

you've got to
organize the movements

of massive amounts of material

then creation of the
blocks that you need.

- [Narrator] Cutting the rock
would be a Herculean task

for laborers equipped only

with copper chisels
and crude hammers.

- The sheer physicality
of this kind of work.

The physical toll that
must take on the body

would have been immense.

- [Narrator] Theory
suggests that

up to 20,000 workers toiled
on the great pyramid,

consuming vast quantities
of raw materials.

Since Khufu's reign, demand
for natural resources

has grown exponentially.

Quarrying now takes place
on an industrial scale.

Reaching far deeper than

the Egyptians ever
imagined possible.

- Modern day quarries and
mines are enormous undertakings

compared to ancient
predecessors.

- [Narrator] Two and
a half miles wide

and three quarters
of a mile deep,

Bingham Canyon
outside Salt Lake City

is considered the
largest mine on Earth.

It's also one of
the most productive.

As of 2018 Bingham
Canyon generated

approximately 19
million tons of copper,

more than any other
mine in history.

- The sort of machinery
that's used on them

is pretty terrifying,
actually awe-inspiring.

- [Narrator] Bucket
wheel excavators,

capable of moving millions
of cubic feet every day,

equivalent to more than 20,000
fully loaded dump trucks.

- We might go and doff
our cap to the Egyptians

for their pyramids.

If they were see our
quarries and our mines,

they would doff
their caps in return.

- [Narrator] Mining was
a much slower business

in ancient Egypt.

Even once stone
had been extracted,

another great
challenge remained.

Transporting it
to the build site.

A recent discovery has revealed
exactly how it was done.

In 2013, a team of archeologists

came across
something remarkable,

hundreds of miles from
the pyramid side at Giza.

Dozens of inscribed
papyrus fragments,

written more than 4,500 years
ago during the reign of Khufu.

- These are
essentially a logbook.

What they tell is that
foreman called Merer,

and he's commanding a ship,

ferrying goods from
one part of Egypt,

all the way up to
the Giza Necropolis

where the pyramids are built.

- [Narrator] Merer recorded
his daily activity,

transporting stone by boat

from the Tura Limestone
Quarry to Giza,

ferrying blocks
from this quarry,

and others along the Nile

ensured enough stone
reached the pyramid site.

All thanks to a
mode of transport

on which the modern
world still depends.

Cargo ships carry
billions of tons of goods

across the globe each year.

And that number
continues to rise.

- We've become very used

to the idea of
containerized transport,

and it affects how we move
stuff around the world.

- [Narrator] Container ships

reach up to 1300 feet in length,

capable of carrying over 100,000
tons in a single journey.

Thanks to their shipping skills,

the ancient Egyptians maintained
a steady supply of blocks

to the pyramid site.

But the biggest challenge
still lay ahead.

- How do you get that
block that you've quarried

and put next to the pyramid
up into the pyramid itself?

- [Narrator] One
recent idea may explain

this long-standing mystery.

- Many Egyptologists suspect
that ramps were used.

- [Narrator] It's
likely engineers used

a large single ramp
leading to the pyramid.

And the ancients knew it was
crucial to get its angle right.

- Anything beyond
six or seven degrees

becomes very, very difficult

to then push a
large block uphill.

- [Narrator] But
keeping the ramp shallow

would force it to
cover a huge distance.

- It would be miles long to
get to the top of the pyramid.

So it would take
longer to build a ramp

than it would take
to build a pyramid.

That doesn't make any sense.

- [Narrator]
Speculation continues

as to exactly how the Egyptians
built their giant monuments.

- Pyramids are so extraordinary

that people have always
struggled to believe

that they could
possibly have been built

as long ago as they were.

- [Narrator] And
their perfection

has become a breeding
ground for wild theories

with some suggesting that
there's something else going on.

- People when faced
by the pyramids,

look at this and think it
can't possibly have been done

without some force from outside.

- [Narrator] Did this
ancient civilization

have alien assistance?

- That couldn't
possibly be true.

The arguments are
fabulously speculative,

none of them plausible,
none of them real.

- I feel quite offended on
behalf of the ancient Egyptians

that their abilities are
called into question like this.

Of course, the Egyptians
built the pyramids.

They did so brilliantly.

- [Narrator] There may be
precious little evidence

to support how the
pyramids were built,

but there's no doubt
that these mighty tombs

were constructed by
skilled Egyptian craftsmen

without any outside help.

Certainly not from aliens.

And the Egyptians
engineering brilliance

didn't stop at the pyramid's
limestone exterior.

- The great pyramid isn't a
completely solid structure.

There are chambers and
pathways within it.

A grand tomb for the king,

with the king's chamber
right at the pyramid's heart.

Today, all that remains

is Khufu's giant
granite sarcophagus

along with two tiny shafts
on the north and south walls.

- Originally, it
was believed that

these could be air shafts
for the burial chamber,

but that seems unlikely.

- [Narrator] Then in 1964,

astronomers made an
extraordinary discovery.

One shaft aligns precisely
with Orion's belt

while the other lines
up with the North Star,

as it would have appeared in
ancient Egypt's night sky,

both shafts rise
at constant angles,

each running for
more than 130 feet

through the body of the pyramid.

- They are intended to
provide a clear sight line

from the burial chamber
up to the stars.

- An engineering phenomenon,

all to guide the king's
spirit after death.

- There's a desire
for the royal soul

to emerge from
the mummified body

and ascend to not only the gods,

but also to travel
up into the night sky

and join with the stars.

- [Narrator] Launch
pads to the afterlife.

But the Pharaoh wouldn't ascend
to the heavens empty-handed.

Egyptian rulers
were often buried

with their most
prized possessions

to accompany them in death.

Gold, silver, and
bronze artifacts

were loaded into
their great tombs

while fine linens and artwork
adorned the secret chambers.

- All the things that made
yourself happy here and now.

So you could carry it with
you into the world beyond.

- [Narrator] But this wasn't
simply about jewels or gold.

Egypt's greatest treasure
was the mummified body

of the god king, which must
be protected at all cost.

- The burial chamber
itself is quite incredible.

It almost looks
like a bank vault.

- [Narrator] Egyptian engineers
are thought to have used

a 3D scale model of
the burial chamber,

a surprisingly modern
technique for construction.

- If you were thinking
about designing something

like a pyramid today, we would
be designing that digitally.

So we'd have a 3D digital model

to understand what the
space was like inside.

- [Narrator] No
expense was spared

in designing the
king's burial chamber.

Engineers devised a way to
plug the passages with stone,

sealing off the tomb,

securing the site where
their king's journey

into the afterlife would begin.

In 2560 BC, after
two decades of work,

the great pyramid of
Giza was completed.

Khufu had created a symbol
of his absolute rule,

towering 479 feet over
the Egyptian desert.

- To see this, the
biggest structure

anyone had ever seen
in all human history.

I mean, it's hard to imagine
what it must've been like.

- [Narrator] Armed with basic
tools and clever engineering

the ancient Egyptians had
created a structural marvel.

- It's staggering to think
for almost 4,000 years.

The great pyramid of Giza was
the tallest building on Earth.

- [Narrator] An
eternal testament

to the power of their empire.

- This is a statement piece,

the wealth, the might, the power

and how important
this person is.

- [Narrator] Originally covered

by a smooth sloping of
fine, white limestone

the monument was once
even more striking,

gleaming in the sunlight.

The last of the seven wonders

of the ancient world to survive.

It's one of the most
well-studied buildings on Earth,

but there's still so
much left to learn.

- In many ways we've just
scratched the surface

and the more rapidly
modern technology develops,

the more we're finding
out about ancient Egypt.

- [Narrator] Often a discovery

raises more questions
than it answers.

In 2017 scientists detected

a previously unknown void
within the structure.

Techniques including
thermal imaging

helped identify a space
roughly 98 feet long

above the giant passageway

leading to the king's chamber.

- It gets people really excited

and people think
there's another chamber.

This could be where someone's
buried and where goods are.

- [Narrator] But it's true
purpose remains a mystery.

Despite archeologists
best efforts,

the great pyramid retains
many of its deepest secrets.

And it's just one of
many pyramids yet to
be fully explored.

The ancient Egyptians
went on to build

more than 80 further
pyramids across the country.

But none surpassed the magnitude
of Khufu's great pyramid.

Over the centuries,

the scale and precision of
construction tailed off.

- They're not being
built in the same way

as those earlier pyramids.

And what happens is these things

don't stand the test of time.

- [Narrator] But why did

Egypt's pyramid
building craze die out?

- Tomb raiders were a massive
problem for the Egyptians.

People who were well aware of
what was within those tombs.

- Of course, it
doesn't take a genius

to work out where
that goal might be.

You might as well
just put a big cross.

- [Narrator]
Eventually, the Pharaohs

were forced to change their
approach to royal burials.

A thousand years after
the great pyramid age,

the pharaohs of the
new kingdom established

a secret burial place
on the Nile's west bank,

the Valley of the Kings.

More than 60 tombs were carved
across this remote valley.

- The Valley of the
Kings contains burials,

which are cut directly
into the rock itself.

- [Narrator] Including
the most famous

Egyptian burial of them all,

the boy king, Tutankhamun.

Today, engineers have dug one
structure deep underground.

Not to protect a king,

but to ensure the continued
survival of nature itself.

Deep in the bowels
of an icy mountain

on the Island of Spitsbergen

lies the Svalbard
Global Seed Vault,

a secure facility where
more than a million seeds

from the world's
agricultural plants are kept.

Constructed in 2008,

the site was chosen for its
position below permafrost

and thick rock over 320
feet within the mountain

where the seed samples
will remain frozen

even if the power supply fails.

- It's a gigantic
safety deposit box,

which holds the world's
largest collection

of agricultural biodiversity.

- [Narrator] The
facility ensures

that biodiverse plant
life could be restored

after a great natural disaster
or global catastrophe.

And as ancient Egypt's
rulers continued

to be buried away
from prying eyes.

The pyramids were
soon forgotten.

But elsewhere their story
was only just beginning.

In a burst of creativity
around the eighth century BC,

one of Egypt's
neighboring kingdoms

began their own
pyramid building craze.

- Few people realize
there are more than twice

as many pyramids over
the Southern border

in ancient Nubia, modern Sudan.

- [Narrator] But
Sudan's pyramids

would be radically different.

- Their angle of incline
is far, far steeper

than the Egyptian ones.

And more often than not, they
are considerably smaller.

- [Narrator] For visitors
these ancient structures

are striking sites to behold,

the last pyramids
of ancient Africa,

but on the far side
of the world, other
empires were rising.

From around 1200 BC,

advanced societies
emerged in the Americas,

the Olmec, Maya, and Aztecs
flourished across the region

developing great civilizations
up until the 16th century.

And they had one
thing in common.

Pyramids.

These civilizations
began constructing

the sky high structures
at a remarkable rate.

- We can literally say
that thousands of pyramids

dotted the
Mesoamerican landscape.

- [Narrator] More pyramids than

in the rest of the
world combined.

Topped with elaborate platforms

they became the
glorious centerpieces

to vast ancient cities.

Believed to house their deities

and serve as tombs
for their dead kings.

But was that the entire story?

Do these mighty structures
conceal a dark and bloody past?

Once the most populous
city in the Americas,

Teotihuacan sprawled over an
area larger than ancient Rome.

- Teotihuacan was
a very large city,

possibly having a
hundred thousand
inhabitants at the peak.

- [Narrator] The largest city

anywhere in the
western hemisphere.

Yet little is known about
the people who lived there.

- Teotihuacan is a major site.

It was prominent until about 600

and then things
began to decline.

- [Narrator] The city
was suddenly abandoned

and it's still not
clear why it's people

and their culture
vanished overnight.

- We have several
signs of destruction.

Monuments were destroyed,
the city was burned.

- [Narrator] Now the
pyramids and ruins

are all that remain of
this once majestic city.

And they offer
insight into the lives

of the Teotihuacan people.

But there have also been
some disturbing discoveries.

Beneath one of the
city's largest structures

known as the
Pyramid of the Moon.

Archeologists were shocked
by what they found.

Underground chambers filled
with animal and human remains,

including human skulls.

- The ritual activity
of the temples

sometimes entailed the
participation of human beings

that were offered up ritually,

individuals that
were killed ritually.

Some were captives of war.

We know that they had
their hands tied up.

- [Narrator] Large offerings,
including human sacrifices

were made regularly in an
attempt to appease the gods.

Some even believed that it
would prevent the apocalypse.

Despite their bloody
and brutal history,

these monuments are marvels
of the ancient world,

still standing centuries

after their creators
all but disappeared.

Pyramids are among the
most enduring icons

of the ancient world.

Even today, they feature
heavily in architectural design.

- Modern architects still
find that shape fascinating,

it's perfection, it's symmetry,

the way that it connects
us back to our history.

And you see that now reflected

in buildings around the world.

- [Narrator] The Luxor
Las Vegas Pyramid

is specifically modeled
on Khufu's grand tomb,

complete with its own
Sphinx and obelisk.

And in Paris, the glass pyramid
fronting the Louvre Museum

is one of the city's
most notable landmarks.

- That pyramid shape is still
something that we desire.

I think there's something
about the symmetry

we seem to have an
affinity or a liking to.

- [Narrator] Pyramids are part
of our common global culture.

Even found on the
U.S. dollar bill,

a homage to Egyptian
ancestry in updated form.

Dating back more
than 4,500 years,

pyramids revolutionized
construction in
the ancient world.

They consumed materials and
labor on an unparalleled scale,

requiring engineering
know-how never seen before.

Today they continue to inspire.

And it doesn't look like
these iconic structures

will be going anywhere soon.

The pyramid, an ancient
design so perfect

it has survived the ages.

[epic music]