All language subtitles for Ancient.Impossible.S01E08.Biggest.Builds.1080p.AMZN.WEB-DL.DD+2.0.H.264-playWEB_track4_[eng]

NARRATOR: How could the ancients
build colossal structures

in less time than we can
construct the biggest buildings

of today?

How could the ancient Egyptians
produce thousands and chariots

with assembly line precision?

Why did the Romans create a
massive, underground industrial

hell where thousands of slaves
never saw the light of day?

Monuments more colossal than
our own, ancient superweapon

as mighty as today's,
technology so precise

it defies reinvention--

the ancient world
was not primitive.

Their marvels are so advanced
we still use them now.

Travel to a world closer than
we imagine, an ancient age

where nothing is impossible.

The biggest builds of
today are the result

of mammoth engineering
projects, huge structures that

define the modern era.

But who are the greatest
engineers of all time?

Could there have been
building projects

just as impressive
in ancient times?

The Romans were not only the
biggest and strongest power

of the ancient world, but
they were also the most

technologically advanced.

They made amazing buildings
and military machines.

They were so ahead of their
time that it's only recently

that modern engineers have
been able to replicate

their techniques.

And one of the Romans
most incredible

discoveries-- concrete.

It's only in the
last 100 years or so

that concrete has come
to play such a large part

in our architecture.

But it's actually a rediscovery.

Amazingly, the Romans were using
it for their biggest builds

over 2,000 years ago.

The science of concrete
was perfected by the Romans

thousands of years ago.

And when the Roman civilization
fell, that science was lost.

And the most amazing example of
this Roman engineering miracle

is to be found here at Caesarea,
on the coast of present day

Israel.

Unbelievably, they built a
huge harbor made of concrete,

and it was one of the
biggest artificial ports

in the ancient world.

Imagine how our cities and
ports might have developed

if this knowledge
hadn't been lost.

It was another 2,000 years
before mankind could replicate

this technology.

When the technology
was rediscovered,

it essentially shaped
the modern world.

Everything around us relies
upon the presence of concrete.

NARRATOR: But what's so
special about concrete?

It can be shaped and molded.

With concrete, the Romans could
make arches, vaults, and domes.

This was revolutionary.

If you imagine the
times before concrete,

you're relatively limited to
what it was you could dream up.

But then the minute
that you could create

these man-made stones in
essentially any shape you

wanted, architects,
they were free to dream.

They were liberated,
and they did dream.

NARRATOR: And at Caesarea,
they dreamed the impossible--

using concrete underwater.

This was something
extraordinary.

In modern times,
underwater concrete

has only been used
for about 150 years,

but the Romans were
using it 2,000 years ago.

This sounds impossible, but
here it at Caesarea, the Romans

made the impossible possible.

I'm standing amidst the ruins
of the impressive artificial

harbor in Caesarea.

This would have been
an incredible sight

in the ancient world.

NARRATOR: The harbor was
certainly an engineering

marvel, over a million cubic
feet of concrete embedded

in the sea.

Just the thought of
building a man-made harbor

was a sign of the
audacity of the Romans.

And then the decision
to use concrete

was even more astonishing.

And the man behind it?

Herod, the Romans'
puppet king of Judea.

He's often thought
of as an evil tyrant,

but because he was in
league with the Romans

he was able to commission some
of the greatest mega-builds.

King Herod needed
a large harbor.

There were no natural
places to anchor ships.

He decided to build
one from scratch.

The harbor itself was
unbelievably huge, big.

Nobody could see such a
big structure worldwide.

It was the largest structures
on Earth at the time,

90,000 square yards.

That's a huge area.

The port extends on either
side of where I'm standing,

to the south over
1,500 feet long,

on the northern side
about 1,000 feet long.

You have to think
of about 40 acres

or 30 football fields are
comprised within the two arms

projecting forward.

He created a water break
that was 180 feet wide.

Huge.

You could have a
highway on top of it.

It extended deeply to the
sea, almost half a mile

into the sea.

NARRATOR: Herod wanted to build
a huge harbor to rival any

in the world, and
that's despite the lack

of a good natural
harbor at this site.

This was because he wanted
his province of Judea

to be the main trading
route for East to West.

His incredible harbor could
accommodate 300 ships.

It dwarfed anything found
here before or since.

See part of the
bottom port over here.

The actual breakwater of the
port of Caesarea is underneath,

and it's sunken
down about 5 meters

beneath the surface when it
extended twice the length out

into the sea.

NARRATOR: The concrete
harbor was so impressive

that King Herod built a
new palace for himself

on the waterfront.

And the port became the catalyst
for a great trading city

and a new capital for Judea.

This port was a
commercial center, a hub.

There's a massive market
in the Western half

of the Mediterranean.

The Roman senators, they want
the goods from the Middle East

and from the Orient.

This became one of the
key harbors that brought

those goods from East to West.

NARRATOR: But how did the
Romans build this harbor?

What was the magic
ingredient that they

used to make the concrete set?

And how did they lay
concrete underwater?

It's only recently that we
have uncovered the truth.

At this concrete factory
in Austin, Texas,

they have the
ingredients prepared.

There are seven ingredients
in marine mix concrete--

quicklime, clay, seawater,
sand, fly ash, large aggregates,

and animal blood, in
this case, pig blood.

NARRATOR: One theory
is that blood was

used to strengthen the mixture.

But the key to underwater
setting lay elsewhere.

They developed a kind of
mortar that had extraordinarily

good lime in it.

And that made it
strong to begin with.

But the real key is
the chemical reaction

that happened when they added
pozzolano sand to their mortar.

NARRATOR: This special kind of
sand came from volcanic ash.

It made the concrete so durable
it could harden underwater.

Luckily, Thanks to
Mount Vesuvius in Italy,

the Romans could find
this sand in abundance.

The fact that Mount
Vesuvius was over 100 miles

away wasn't going to stop them.

So they had to ship
over this volcanic sand

in enormous amounts.

We're talking about 44 ships
with a 400-ton capacity,

without that, this
artificial harbor could not

have been built.
So it's something

that the Romans
develop and perfect,

and it allows them
to pour this and have

it harden in the saltwater.

NARRATOR: Marine
concrete hasn't been made

in this way since Roman times.

Is it possible that it
can be recreated today?

We work with
concrete all the time.

We're going to try
today to recreate

ancient marine concrete, like
used at the ancient harbor

of Caesarea.

NARRATOR: For the Romans
to discover 2,000 years ago

that volcanic ash
would have this effect

was an enormous
technological leap.

And this was done on
an industrial scale.

Hundreds of slaves would
have been used to carry, mix,

and pour the materials.

It must have been a
massive operation.

This ancient concrete
mix is going underwater.

It will be ready for
testing in 30 days.

We're going to find out if this
ancient concrete recipe really

works.

NARRATOR: The ancient
empires of the Mediterranean

depended on sea power
for military dominance

and for trade.

The Romans were no different.

In fact, they always took
things to another level.

They had to have the best
ships, the best crews,

and to go with them, the
greatest, most up-to-date

ports.

It's not so different today.

The major cities of
the world are ports.

90% of all the world's trade
is still transported by sea.

In ancient times, great cities
such as Carthage and Alexandria

grew up around their ports.

But the Romans were able to
do what for everyone else

was impossible.

They could build a
port like no other.

It was built bigger, and
it was built to last.

And at Caesarea today, the
massive 2000-year-old concrete

jetties can still be seen
just under the water.

As a diver, what you see just
below the surface of the water

is huge construction.

The poured concrete is intact.

And as you swim along, you'll
see actually the imprints

of the wooden framework into
which the concrete was poured.

NARRATOR: This is remarkable.

This concrete is
2,000 years old,

and it's still
intact on the seabed.

How did the Romans lay
this concrete underwater?

It's an engineering marvel.

Specially made wooden
barges were partly

filled with concrete and floated
into position, then anchored.

More concrete was
then poured in.

So you set those up,
you pour in the concrete.

And as it settles and
hardens and solidifies,

you can sink it down to the
bottom, where it would harden

and be able to withstand
the force of the sea.

And they were going to
build these in sections.

It's just a massive enterprise.

NARRATOR: This process,
repeated again and again,

eventually led to the
massive concrete jetties

rising from the sea.

And the giant jetties would
probably still be in use today

if they hadn't been built on a
seismic fault. Over the years,

earthquakes have
taken their toll.

Still, the concrete
has survived.

Modern concrete routinely
shows signs of degradation

after just 50 years.

The strength of
concrete can be tested.

And at this engineering
company in Austin, Texas,

they have a special
machine to do just that.

Basically what we do is
we put a concrete cylinder

in the press, and apply a load,
and see how much compressive

force it can take.

NARRATOR: New concrete
like this holds out well.

Ooh!

NARRATOR: If they had a similar
cylinder of Roman concrete,

they could precisely
measure its strength.

In the nearby concrete factory,
a mix of Roman concrete

has been left to harden.

And now the time has come.

How has the special Roman mix
of underwater concrete fared?

Well, to me this is amazing,
that this block of marine mix

concrete actually formed.

I didn't think it was
going to form like this.

And you know, the
crazy thing about this

is that this concrete
gets stronger over time.

And it's only been
30 days hardening.

NARRATOR: This is
ancient technology

at work, underwater concrete
2,000 years ahead of its time.

It's impossible to believe
that this marine mix concrete

sat under water and hardened.

It's as hard as modern concrete.

NARRATOR: But exactly
how hard is it?

How does Roman marine concrete
hold up to modern testing?

For the first time, the
engineering workshop

has a sample and will test
the pressure it can withstand

in PSI, pounds per square inch.

That technology is a
couple thousand years old,

and I'd be surprised if it
got up to 200 or 300 PSI.

NARRATOR: Soon it becomes
clear that after just 30 days

setting, the Roman
mixed concrete

is bearing up remarkably well.

Anything beyond 300 PSI
would be astonishing.

This came in at
nearly 400 PSI.

For an ancient technology,
that's incredible.

NARRATOR: With every
week, the concrete

will get stronger and stronger.

This concrete mix was 2,000
years ahead of its time.

And that's without all
the modern machinery

used in the industry today.

We're making modern
concrete right behind me now.

It's impossible to think that
all of this modern equipment

is needed to replicate what the
ancient Romans were doing 2,000

years ago.

NARRATOR: Many of the biggest
builds of the modern world

are factories and
places of industry.

Even food, which used
to be made in the home,

is now produced on
an industrial scale.

In ancient times, could they
have had factories like this?

Surely impossible.

But these strange ruins on a
hillside in southern France

have a remarkable story to tell.

For years, they were a
puzzle, but now history

is being rewritten.

We normally think that it was
the Industrial Revolution that

gave us the modern
idea of factories.

And before that, we
had cottage industries.

However, we've now got to
rewrite our understanding.

NARRATOR: The mysterious
ruins are at Barbegal,

near the town of Arles.

And the clue to
what went on here

lies above, beyond the hillside.

Here we find
something spectacular.

We're in Southern
France at Barbegal,

and this is a Roman aqueduct.

But it's unlike any Roman
aqueduct you've seen before.

NARRATOR: What makes
that so special is

how it was put to use.

The water from this aqueduct
served a very special purpose.

What's so significant
about this site

is that there were 16
mills powered by water

right along this hillside.

A huge series of water wheels.

This is something that's
totally extraordinary.

We haven't seen the
like until today

with modern
hydroelectric systems.

This is a huge undertaking.

They actually turned
a natural hillside

into a vast watermill system.

This is a really massive
mechanical operation,

and it worked.

NARRATOR: The Romans didn't
invent the watermill.

The ancient Greeks were
the first to use them.

But nothing like Barbegal
had ever been built before.

Together, these waterwheels
comprised one of the biggest

builds of the ancient world,
a waterwheel super factory

in the 2nd century AD, which
has never been matched since.

And that's despite
waterwheels remaining

in use for another 2,000 years.

It wasn't until the age of
steam that the mechanics

of waterwheels were surpassed.

But not only was
Barbegal massive,

it was also highly efficient.

It was much more advanced than
any waterwheel technology that

followed it.

Many waterwheels, like this
17th century mill at Hereford

in England, are powered by water
hitting the bottom or middle

of the wheel.

If we had a higher
drop what we'd do

is we'd be bringing the
water in over the top

and have an overshot
shot wheel, so the water

fills all the buckets
and turns it around.

More efficient, but you need to
have that big a drop of water.

NARRATOR: Without
a steep incline,

a stream can still
power a waterwheel.

But at Barbegal, the Romans
made use of the high drop.

The water pouring down onto the
wheels, 66 gallons per second,

made each of these wheels 2
and 1/2 times more efficient.

But it's not just the mills
here that were an engineering

marvel.

Getting the water to them was
a seemingly impossible task.

Between the aqueduct and the
mills was the top of the hill.

What the Romans do is
they actually physically

cut a channel into the
top of the hillside,

so the water can be
fed through, and then

it can hit the top of the
mill with absolute force

and then charge down
65 feet to the bottom,

creating a huge amount
of force and momentum.

NARRATOR: The massive cutting
was made through solid rock.

And it shows the incredible
ambition of the Romans.

For them, when it
came to building,

no obstacle was too big.

What's really impossible,
just think about Barbegal.

Somebody had the vision to
say, we'll capture water

six miles away,
build an aqueduct,

stick it through a
mountain, and then we'll

build a whole set of
steps of water wheels

to harness all the energy--

16 watermills all stacked up.

The scale was immense.

This was able to put out
about 4 and 1/2 tons of flour

every day.

NARRATOR: But what was
all this flour for?

Today's mega bakeries
use machinery

on an industrial scale to
produce vast amounts of bread

for our towns and cities.

Why at Barbegal was the
huge miling complex needed?

We know there were at least
12,500 people living in Arles,

and then some more
military on top of that.

It looks like the
wheels of Barbegal

produced enough bread to
feed the entire population.

NARRATOR: Keeping people
fed was all a part

of the Romans' grand plan.

Military might alone doesn't
hold an empire together.

Very interestingly,
there is no point

in having an empire if your
people are either subversive

or starving.

So of course the way
to keep them onside

is to keep them well-fed.

NARRATOR: During
Barbegal's peak years,

the vast Roman Empire was
growing at a breakneck pace,

bringing people together
into urban centers,

keeping them under
control, civilizing them.

It was all part of
how the empire worked.

A city could be fed.

The people were then free
to work, to make goods.

Goods equals wealth.

Wealth equals power.

A water wheel-- the power
of the Roman Empire.

NARRATOR: But the empire
didn't go on growing forever.

One theory as to why the Roman
Empire eventually declined

is that it had so much slave
labor there was no incentive

to embrace new technology.

Barbegal is important because
it shows the opposite.

It's a water-powered factory.

I think when people
learn about Barbegal,

they're always
shocked and amazed.

Today, we think
about factories, we

think about industrialization,
we think about modern times.

But here the Romans
are showing us

what they were able to
achieve on a grand scale,

on an industrialized
scale 2,000 years ago.

I think it's rightly
earned a reputation

as being the greatest
concentration

of mechanical power
in the ancient world.

It's phenomenal.

NARRATOR: Remarkably,
this hugely important

archaeological site has only
really been fully understood

in the last few decades.

And it's been a revelation.

Before this, no one imagined
such a place could exist.

Is it possible there could be
other sites like this, which

have yet to be discovered?

The Barbegal mills are
a real success story.

As a historian
and archaeologist,

you're constantly
thinking, maybe,

just maybe there's another
example like this that is just

waiting to be found.

And what's really interesting
about them is that, in a way,

this is the Industrial
Revolution 16

centuries before the Industrial
Revolution officially happened.

NARRATOR: Throughout
the centuries,

warfare has driven technology.

Great scientific breakthroughs
have been made in our quest

for new means of destruction.

Defense is a huge industry,
and is responsible for some

of our biggest builds.

But could there have been an
ancient military factory as big

as those of today?

This is the Joint Systems
Manufacturing Center

in Lima, Ohio.

It's the home of the Abrams
tank, 70 tons of imposing

military might.

All tanks for the US
Army are built here.

During World War II,
it mass produced tanks

at a phenomenal rate.

Victory in Europe
depended on it.

It's still one massive
factory with a highly skilled

workforce.

It's great knowing that
you're building the best product

in the world, and
soldiers are safe,

one of the best-built
tanks in the world.

This is the first time
that I've been on a tank.

And I have to say,
it's a real thrill.

I mean, up here you really get
the most incredibly commanding

view.

I'm a cavalry man at
heart, and he's very

much like being on a horse.

NARRATOR: In many ways, the
tank is the modern equivalent

of an ancient fighting
chariot, a mobile,

state-of-the-art fighting force.

But it's also
a command center,

just like chariots were
mobile platforms or artillery

on the battlefield.

It's not infrequently said,
and I've often said it myself,

that the chariot is
the ancient tank.

What it does is
provide mobility.

NARRATOR: The fighting chariots
of the ancient Egyptians

were the meanest machines
on the battlefield.

But were they factory-made,
like the tanks at Lima?

It's almost
impossible to believe,

but over 3,000 years ago,
the great Pharaoh Rameses II

had his own huge factory
for the state-run production

of these fighting machines.

We have evidence of
Rameses' chariot factory

both archaeologically
and in tomb paintings.

And what we can tell is it was
on a massive scale, state mass

production just like
this tank factory.

Rameses demanded chariots,
masses of chariots.

They were needed for a battle,
a big battle, the Battle

of Kadesh, the
greatest chariot battle

that the world has ever seen.

NARRATOR: In 1274 BC,
Kadesh was the culmination

of the incredible mass
production of chariots

under Rameses II.

And it was here in the
desert of modern day Syria

that the Egyptian army clashed
with the other superpower

of the day, the Hittites.

With thousands of
chariots on each side,

this was chariot warfare on
an unprecedented and massive

scale.

That's an awful lot of
chariots on the field.

And you imagine them
swirling around in the dust.

It's a thick dust storm,
and it's a real dogfight

as they're all
trying to outmaneuver

each other and the archers
to pick off their opponents.

NARRATOR: But how
could so many chariots

have been made, and where?

The factory that produced
the Egyptian chariots must

have been massive,
big enough to supply

the huge numbers of
chariots needed for the war

with the Hittites.

And a possible site has been
identified at Pi-Ramesse

in the Nile Delta.

What we have is tables for
something like 480 horses,

which means 240 chariots.

We have a training
ground, and we

have a place which is
said by some people

to be a chariot factory.

NARRATOR: The site on the Nile
has yet to be fully excavated.

But one thing we know for
sure is that, remarkably,

the factory used an assembly
line, just like the tank

factory at Lima.

So here we are at
the assembly line.

And you can see tank after
tank after tank stretching back

there.

You're taking preformed pieces.

You're bringing them
to an assembly plant,

and skilled workers are
putting things together.

It is almost
impossible to imagine

that over 3,000 years ago
the manufacturing processes,

the systems for making military
hardware would be the same

as they are in the 21st century.

But they were.

It was the same principle--
assembly line factory work.

Henry Ford is known as the
creator of the production

line in the 20th century.

But 3,000 years ago,
impossible to believe,

the Egyptians did the
same, an assembly line

that churns out
relentlessly chariot

after chariot after chariot.

NARRATOR: On the floor
of the tank factory,

the individual
components come together.

They're state of the art and
made by specialist teams.

It was just the same
in the chariot factory.

First, the body
of the chariot--

lightweight wood curved
into shape by steaming it.

Just big enough for
two standing men.

The undercarriage was a
fixed axle and a central pole

made by one artificially
bent piece of wood.

Quite a large wheelbase
directly beneath the body

to keep the chariot stable.

The frame for the horses
is also made of bent wood,

and it attaches to
the end of the pole.

You can't have a
chariot without wheels.

One quick assembly, a deadly
mobile fighting machine.

NARRATOR: The Egyptians
understood the importance

of using the perfect materials
and imported wood especially,

in particular ash.

Even today, one
specialty builder

of sports cars in
England still uses ash

just as the ancient
Egyptians did.

This is the Morgan Car Factory,
where skilled craftsmen have

been assembling cars in
this way for over 100 years.

Ash, of course, would be
ideal for a combat vehicle,

a chariot, for the same
reasons that we use it.

It's not only extremely
strong, it's lightweight.

The lighter you could make
a structure like that,

the easier the horses could
pull it, the more flexible

it would be, and the more
effective fighting machine.

Being flexible, it can
act as a shock absorber.

It's the same with
us here in Morgan.

The frame will flex and
bend with the chassis,

and this all adds to the
road holding and the handling

of the cars.

NARRATOR: The factory here
makes around 100 tires

a month, handcrafted
with skill and precision.

Rameses II needed chariots
in their thousands.

The fact that his chariots
could be mass produced

was in itself a source of wonder
and terror for his enemies.

Rameses' systems
were so advanced, so

efficient in producing the great
numbers of military vehicles

that he needed, it's
almost impossible

to conceive that
factories of this scale

existed 3,000 years ago.

But they did.

NARRATOR: Some of the
most iconic buildings

ever constructed are huge
cathedrals, such as Notre Dame

in Paris and St.
Paul's in London.

But incredibly, one of the
biggest builds in history

is a cathedral
from ancient times.

In 6th century Constantinople,
when the magnificent cathedral

of Hagia Sophia rose
from the ground,

it was as if the
impossible had happened.

This is the Hagia Sophia.

It is one of the most impressive
architectural constructions

in the world.

It exerted an influence
for 1,000 years

after its construction.

"Hagia Sophia" means holy
or divine wisdom in Turkish.

And the building is
the supreme masterpiece

of Byzantine architecture.

And for almost 1,000 years,
it was the biggest cathedral

in the whole world.

NARRATOR: Still standing
after 1,500 years,

with minarets added
at a later date,

this was an incredible build
with techniques centuries ahead

of its time, a Roman Christian
cathedral that was a revolution

in architecture.

This is such an amazing space.

You've got something
that's intact,

something that's constructed
in the 6th century AD.

And the thing is, it's
hard to get a sense of how

massive this space is, because
there are so many openings.

There's so much light.

It's almost impossible to
imagine what people thought

of it when they first saw it.

They must have thought that
they were looking at something

impossible.

They wouldn't have understood
how it stayed upright.

A lot of people thought
that God himself

was holding the building.

That's how special it was.

NARRATOR: And this was
exactly the intention.

The man behind it,
the Emperor Justinian,

needed to assert
his political power.

To do this, he wanted
to be linked with God

in the most visible way.

He wanted it to represent not
only his greatness on Earth,

but God's greatness
in heaven, and to draw

that link for
people to say "I am

God's representative on Earth."

NARRATOR: In the 6th
century, the Roman Empire

was based in Constantinople,
modern day Istanbul,

but the empire was fading.

Justinian knew that if
he didn't make his mark

in some grand way, he would
be just a footnote in history.

He wanted to be great.

He was determined that as well
as being something massive,

his cathedral was going to
be something completely new.

So he didn't go to the
master builders of his age.

He went to mathematicians.

He depends upon these experts of
math, and geometry, and science

to go in a new direction, to
create something that no one

had ever seen before.

To understand it, we need
to start with the dome.

NARRATOR: The dome is the
most impossible achievement.

It's 102 feet across
and 180 feet high.

It's huge.

It's broader than the dome
of the Capitol building.

And that was built
1,300 years later.

But the most amazing thing
is that the dome doesn't

seem to be resting
on anything solid.

Essentially, you
have this massive dome,

which seems to just rest
lightly on these 40 windows.

So it's something that's
ethereal, almost light

about it.

And for a dome to be built on a
square base rather than a round

one was something
completely new.

For the Romans to achieve
this was truly remarkable.

These four piers are
essentially building supports.

And in the Hagia
Sophia, they're huge.

They were built to
support the dome.

Well, four arches were
built on top of the columns.

Then the spaces in between
were filled with masonry.

They fill in the upper
corners of the space,

and so form a circle of
support for the dome.

This was a giant
leap in architecture.

It must have been incredible
then, because today it

still looks awe-inspiring.

NARRATOR: Hagia Sophia is
huge, about 65,000 square feet.

But the speed of its
building was impossible, too.

Normally, cathedrals
took decades to build.

The construction of Notre
Dame hundreds of years

later took over a century.

And just the dome of the
Capitol building took 11 years.

This is a large
structure that's

built in a mere five years.

That is incredible.

To give a modern comparison,
the Burj Khalifa in Dubai,

which is the tallest
building in the whole world,

took six years.

And that's with all the modern
technology that we now have.

That is a tribute to Justinian's
vision to make this engineering

miracle happen.

NARRATOR: Some of the biggest
builds of the ancient world

were factories and
places of industry.

And just like today, some of
the most impressive of these

were built because of
our insatiable desire

for precious metal.

The Romans' need for
copper and silver

brought them here, to
Rio Tinto in Spain.

And for 2,000 years, the
mine held a dark secret deep

beneath the surface.

This is the Rio Tinto mine
in the heart of Andalusia

in Southern Spain.

It's absolutely vast,
almost 20 square miles.

The first people to
start exploiting metals

in these hills were
over 5,000 years ago.

In Roman hands, this mine became
the single greatest mining

complex in the whole
of the ancient world.

NARRATOR: And it
was here in 1919

that an astonishing
discovery was made--

a huge wooden wheel
buried deep in the ground.

Further investigation revealed
that it was almost 2,000 years

old.

But what was it for?

The answer is almost
impossible to believe.

A clue was found here, at a gold
mine in Dolaucothi in Southern

Wales, a similar wheel
and well-preserved enough

for a scaled down
replica to be made.

Remains of that wheel
were found 150 foot down,

so far down that it's
reasonable to expect that more

than one wheel were used.

And this is a replica of
what one of those wheels

may have looked like.

NARRATOR: It became
clear that the wheel was

used to lift water, to prevent
the mine from flooding.

Water from the bottom was
scooped up, and then fell out

at the top, into a channel
that drained it away.

And someone must have stood deep
underground turning the wheel.

What a horrendous job,
a human hamster in near

pitch black conditions.

The Romans were masters
of waterwheel technology.

But with a waterwheel, normally
moving water turns the wheel.

At both Dolaucothi and at
Rio Tinto what the Romans did

was turn that
concept on its head.

They used manpower
to turn the wheels,

and then the wheels
moved the water.

Move the water, drain
the mine, miners work.

Genius.

NARRATOR: But could a
large wooden wheel really

have been any use
here at Rio Tinto?

This mine is massive,
and the Roman shafts

went deep into the earth.

We now know that at Rio
Tinto, the use of these wheels

was taken to
impossible extremes.

Underground caverns carved
by hand from the earth,

and inside--

eight pairs of
huge water wheels,

powered by slaves
walking the wheels.

To a modern engineer,
it would seem incredible.

To the ancients, it must
have seemed impossible.

But it was an impossible
task that the Romans

faced and mastered.

This was ancient engineering
on a massive scale,

and it made the
impossible possible.

NARRATOR: The
wheels were probably

prefabricated and
constructed within the mine.

Building a whole series
of these huge water wheels

underground is
almost beyond belief.

Today, it would be incredible.

2,000 years ago,
simply impossible.

As the slaves trod
the wheels, the water

was channeled from
one pair to the other,

eventually rising over 100
feet before being drawn

to the surface by a
huge Archimedes screw.

This wasn't hell on Earth.

It was hell deep
within the Earth--

dark, hot, and working with
toxic, mineral-soaked water.

The slaves who operated
these waterwheels had the worst

job in the whole mine.

Their life expectancy
once they got down here

was about 12 to 16 months.

It was that poisonous,
and they were constantly

coated in the water.

And when they finally died,
which they inevitably did,

the Romans didn't even
bother taking their bodies

to the surface.

NARRATOR: But whatever
the terror of the wheels,

they were truly
an ancient wonder,

an incredible,
fantastic construction.

Unbelievable structures built
with techniques thousands

of years ahead of their
time, the biggest builds

of the ancient world were as
astonishing and awe-inspiring

as anything built today--

a world of wonder, of terror,
and of the impossible made

real.