All language subtitles for Ancient.Engineering.S01E06.Secrets.Of.Angkor.Wat.1080p.AMZN.WEB-DL.DDP2.0.H.264-NPMS_track3_[eng]

- [Greg] We are surrounded

by extraordinary
feats of engineering,

constantly pushing the
boundaries of what's possible.

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

- [Greg] Gigantic cities,
amazing infrastructure,

and ingenious inventions.

- Engineering is the key to
turn dreams into reality.

- [Greg] To reach
these dizzying heights,

today's technology
relies on breakthroughs

made by ancient engineers.

- It's mind boggling
how they did this.

- [Greg] 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

that is in itself impressive.

- [Greg] 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?

- [Greg] Now, it's
possible to unearth

the secrets of the
first engineers.

- They managed to
construct edifices

that has survived
the ravages of time.

- [Greg] And reveal how their
genius laid the foundations

for everything we build today.

[dramatic music]

Since the planet's very
first buildings were created,

pioneering engineers
and architects

have been united by a single
driving force, religion.

Divine inspiration has led

to groundbreaking
construction techniques,

pushing the limits
of engineering.

Great temples built
to honor the gods

and it continues to this day.

- Religion is still an
incredibly important part

of the modern world.

- [Greg] Many are
minimalist in design

like India's Lotus Temple
constructed in under 10 years.

Sheathed in pure white marble,

27 blooming petals
cover the structure.

But in the ancient world,

temples were often
far more elaborate

built over decades
or even centuries.

- Nothing really compares
with the grandeur

and the splendor of
the ancient temples.

- It's a building that all

the ancient cultures
have in common.

- [Greg] No expense was spared

as engineers sought to
create ever greater wonders.

- Primitive tools and
technology were not enough

to hold back their ambition.

- [Greg] They achieved
breathtaking buildings,

each with its own story to tell.

But one stands
out from the rest,

hidden deep in the
Cambodian jungle,

a temple to eclipse all others,

Angkor Wat.

A 900 year old complex

rising from the flood
plain of the Mekong River.

- It is one of the largest

religious structures
in the world.

- [Greg] A vast monument
covering more than 400 acres.

- You can't really fail to
be impressed by Angkor Wat.

And when you walk
through the corridors,

it's an incredible experience.

- [Greg] Stone shrines
ascend one upon the other,

as if reaching for the heavens,
endless hallways carved

with some of the longest
reliefs in the world,

and at its center a
magnificent structure

as tall as the
Sydney Opera House.

- It's a home fit for the gods.

- [Greg] But Angkor Wat is
about more than sheer scale.

It's also a masterpiece
of craftsmanship,

sculptural decoration, and
of course, engineering.

The temple is accurately
oriented to the setting sun

and 18 further
astronomical alignments

appear to be built
into its fabric.

This precision stone masonry
not only honoring the gods,

but also imperative for
the temple stability.

Constructed in a monsoon
plagued swamp land.

- This would have been
an astonishing challenge

to get this thing built in a
way that just didn't sink in.

- [Greg] It was completed
in just 30 years.

In comparison, some of the
great medieval cathedrals

took over a century to build.

Angkor Wat was constructed on
a completely different scale

and still stands
many centuries later.

- Even today, it's an
incredible building.

- [Greg] Many claim
the power of the gods

must have inspired
such engineering genius

to produce the peak of
temple construction.

And Angkor Wat is still
shrouded in mystery.

How did an early society
with little technology

build these colossal structures?

- Today, we have modern
building tools and techniques

that really help
engineers and designers

push the boundaries
of creativity

when designing and
building places of worship,

but really nothing compares
to those ancient buildings.

- [Greg] And what exactly

was this ancient
wonder designed to do?

- We have many ideas,

but we're always making
best guesses on the basis

of what archeological
evidence there is to date.

- [Greg] Was it purely
a house of worship

or did it serve another
more mysterious function?

To fully understand its
secrets and engineering,

we need to look further back

to what could be the
very first temple.

A divine design built
by a civilization

thought to have no metal tools,

no formal society, or
even a written language.

How could such a
primitive culture

build a monumental
temple to the gods?

In 1963, a survey of
Southeastern Turkey

revealed broken slabs of
limestone scattered on a hill.

Initially, they were
assumed to be the remains

of an abandoned
medieval cemetery.

But 30 years later, German
archeologist Klaus Schmidt

decided to investigate

the stone littered
hilltop for himself.

- He immediately tweaked
what he was looking at

and he realized that
this was an earlier site

and this had to be
highly significant.

- [Greg] Buried
beneath the surface,

Schmidt unearths something
extraordinary, Gobekli Tepe,

gigantic carved stones, crafted
and arranged in circles.

Radiocarbon dating produced
astonishing results.

The site was around
11,000 years old,

built just after the
end of the last ice age.

- It coincides with
the dates we have

for the very
beginning of farming

- [Greg] More than 5,000 years

before the invention
of the wheel,

somehow these elusive
peoples overcame

immense engineering challenges

to produce giant stone monuments
in a sprawling complex,

including T-shaped monoliths

ranging from 7 to
18 feet in height.

- This is a massive undertaking

to put together these
kinds of shrines.

The size of these
stones is extraordinary,

higher than our head height.

- They have to be chopped
out of the limestone bedrock.

They have to be prized out and
then they have to be dragged

to the place of construction.

And there, they have
to be carefully carved.

- [Greg] An operation
that would have required

hundreds of people

with only simple stone aged
tools at their disposal.

- We're looking at
quite a remarkable

engineering feat to do this.

- [Greg] So was this
mysterious place a home

or an ancient holy site?

Clues may lie on the
stones themselves.

- Many of these stones are
carved in intricate detail

including mammal-like creatures,

bird-like creatures,
lizard type creatures.

- And in the center, there's
two large T-shaped stones.

We also see that
they have human forms

and we can see their hands
and their arms represented.

- [Greg] These carvings
may depict the bodies

of stylized people or
their mysterious deities.

It's led some experts to believe

this must have been
a place of worship.

- Archeologists have
argued that Gobekli

is some kind of ritual site.

It's highly unlikely that this
was a permanent settlement.

- [Greg] It seems early
prehistoric communities

thought the best way
to keep the gods happy

was to build and decorate
monuments in their honor,

but surely lifting these stones

required some kind of
engineering technology?

Even today, it would
present a challenge,

but it would have
been infinitely harder

before the invention
of the wheel

and another engineering
breakthrough, the pulley.

A mechanism designed to make
it easier to move heavy loads,

a pulley can have the
force needed in lifting,

effectively doubling the weight
a single person can lift.

Add multiple pullies, and
the figure keeps on rising.

Onboard a 17th century ship,

a single deck hand could
use a pulley system

to haul up a sail weighing
several times his own weight.

And in the industrial era,

machines developed ever
greater lifting power.

Combined with engines
and hydraulics,

the biggest cranes still use
the physics of the pulley

to move insanely heavy objects.

- Cranes are an
incredibly important tool

in modern construction.

There are very few structures
that I can think of

that wouldn't require a
crane for some reason.

- Crane technology has got
more and more powerful,

so we can lift higher, faster,

heavier weights
than ever before.

- [Greg] Standing 820 feet tall,

Big Carl is the world's
largest land-based crane

powered by 12 engines

and capable of lifting
up to 5,000 tons.

But in the millennia
before the invention

of these technologies,

how did the ancients move
monumental stone loads?

It's an engineering conundrum

that's puzzled
experts for centuries.

Nowhere more so than
at one prehistoric site

in Southern England, Stonehenge.

- Stonehenge is one
of those absolutely

iconic archeological sites.

- [Greg] Dating back
more than 5,000 years,

the monument is a
circular arrangement

of massive sarsen stones,
each way around 25 tons.

Most archeologists now agree
the stones were both carried

via water networks
and hauled over land

before being raised
into position

using plant fiber ropes
and timber platforms.

Given the huge efforts involved,

was Stonehenge an
important ancient temple?

In the 18th century,
a discovery suggested

that the standing stones
hadn't been placed at random.

Instead, they seem to
be precisely laid out

for one specific function.

- All the stones of
Stonehenge were built

around an axis of symmetry

and that axis was
on the solstice line

pointing out to the Northeast
to midsummer sunrise

- [Greg] Stonehenge was designed
to mark the longest day,

when the sun rises directly
over the Heel Stone

and casts a long shadow
that enters the circle

through the main entrance.

Not only did an
ancient civilization

raise and carve
these giant stones,

but they aligned them perfectly
with astronomical events,

a real feat of
precision engineering.

By observing the sun's movements

and coordinating hundreds
of well-organized people,

ancient engineers created a
masterpiece still admired today.

- There is something
very special

about Stonehenge as a place

because of its special
solar alignment.

- [Greg] It leaves little doubt

that those who built
Stonehenge were as interested

in the sky above as
in the land below.

So was this ancient monument

some form of prehistoric
solar observatory?

Humanity's fascination
with the sky above

hasn't diminished
across the millennia.

Today, one of the largest and
best developed observatories

in the world is located on the
summit of Mauna Kea, Hawaii.

Constructed over 13,000
feet above sea level

in a place with little light
pollution, engineers have built

more than a dozen
world-class telescopes here.

Most powerful is the
twin Keck observatory.

Each telescope stands eight
stories tall, weighs 300 tons,

and operates with
nanometer level precision.

Equipped with two 33
foot wide mirrors,

the twin telescopes have
produced incredible results.

Images of distant objects from
across our galaxy and beyond.

Another of the great
ancient civilizations

seems to have shared
this obsession

with the heavens, Ancient Egypt.

From 3,500 BC, Egyptian
engineers built

some of the greatest
temples in world history.

- Egypt was known anciently

as the most religious
land of all.

- [Greg] Their monuments
emphasized order,

symmetry and grandeur,

and were seen as houses
for the gods or kings

to whom they were dedicated.

- The ancient Egyptians were
prolific temple builders

because the gods were very
critical to their society.

- [Greg] But what drove
the ancient Egyptians

to build temples on
such a monumental scale?

One of the greatest was
erected in 13th century BC

by the Pharaoh Ramses the Great,

the twin temple of Abu Simbel.

- The template is
a huge structure

with everything
cut into the rock

rather than built on a
flat surface outside.

- [Greg] Carved directly
out of the mountain side

dedicated to multiple
ancient Egyptian gods,

it also functioned
as a lasting monument

to the king and his
queen, Nefertari.

Four seated colossi
of Ramses the second

guard the 98 foot high
Grand Temple entrance

- The whole pylon gateway
and the statues themselves

are all carved as one
with the living rock.

- [Greg] With only simple tools,

the ancient Egyptians
bore over 200 feet

to Abu Simbel's inner chamber.

And this temple too
is precision aligned.

On key dates,
daylight penetrates

deep into the temple interior.

Once on the 22nd of February,

celebrating the agriculture
and cultivation season.

And again, on the
22nd of October,

marking the onset of
the flooding season.

The statue of Ramses the second

and a moon are
brilliantly illuminated.

- Where you have a dark space

that is just suddenly
lit up at certain times,

it's hard to express
how impressive

that would be if you were there.

- [Greg] While the
statue of Ptah,

god of the Egyptian underworld,

remains in perpetual darkness.

- This temple is a true example
of ancient Egyptian genius.

- [Greg] Abu Simbel survived
through ancient times,

only to be threatened
by the modern world.

Following the decision
to build a dam at Aswan

in the early 1960s,
it was revealed

that the temple would be
flooded by the rising Nile.

But engineers came up
with a remarkable plan

to ensure its survival,

move the entire
16,000 ton structure.

- UNESCO launched an operation
to rescue the temple,

so it was cut into small pieces.

- [Greg] Ramses
temple was sliced

into more than a
thousand blocks,

each weighing between
3 and 20 tons.

They were moved to a desert
plateau 210 feet higher

than the original site, well
above the new water line.

It took more than two
years of painstaking work,

but eventually the blocks
were all pieced back together.

- It was so interesting
to see the way

in which they deconstructed
and reconstructed

this monumental building
from Ancient Egypt.

- [Greg] A vast
engineering jigsaw puzzle.

In 1968, Abu Simbel reopened
in its new higher location.

This remains one of
the greatest feats

in the history of archeology,

an iconic Egyptian
temple rescued

thanks to epic engineering.

But Abu Simbel was far
from the largest temple

constructed in Ancient Egypt.

- The great temples were
built to impress mainly

to make a point about
who you were on Earth

- [Greg] Exhibiting features

that demanded
formidable engineering

combined with great
artistic flair,

towering obelisks, immense
gateways, and vast halls.

Achievements never seen
before in the ancient world

and one out shown
all others, Karnak.

Sitting on the East bank
of the Nile in Luxor,

it's the largest religious
complex ever constructed

in the ancient kingdom.

- Structure's going off

for hundreds of meters
in every direction.

- It's mind boggling
array of temples,

shrines, sacred
roots, it's enormous.

It's the most stunning
temple on Earth in many ways.

- [Greg] Covering an area
of more than 250 acres,

Karnak is bigger than
some ancient cities.

At the heart of the complex
is the Hypostyle hall.

Today, it's drenched
in sunlight,

but originally the
hall was designed

to protect the gods from
the beating midday sun.

- The Hypostyle hall would
have been completely covered,

so it'd be quite dark.

- [Greg] The royal builders
faced an immense problem.

Enormous beams were needed
to span the vast distances

between columns, resting on
these would be a huge roof.

- The main challenges
with a single span roof

are stability and strength.

You've gotta take into
account the material

that you're building it out of

and it's gotta be able to
support its own weight.

- [Greg] Egyptian engineers
needed something stronger

than the limestone blocks used
to construct the pyramids.

- Sandstone was easily available

from the quarries to the South

and also had better qualities
for support than limestone.

- [Greg] A tough material,
perfect for the Hypostyle hall.

The first step was to erect

the towering sandstone
columns 49 feet high.

- There are a few theories

as to how these columns
are put together.

I mean, clearly they quarried
in blocks in separate drums

'cause you can see the
various components of them.

- [Greg] Each piece
weighs over four tons,

too heavy to be
lifted by laborers.

So ancient engineers
must have invented

an ingenious new method.

- How you actually
construct these,

you need some kind of
scaffolding and it seems

the Egyptians might have
used natural scaffolding.

- [Greg] The theory
is that every time

a layer of stone
drums was added,

the space around was
filled with a layer of sand

to create a new
working platform.

- Working all the way
til you've got at the top

and then you then start
removing that sand.

- [Greg] It left behind a
forest of 134 perfect columns,

most as tall as a
seven story building.

And with roof beams in place,

Egyptian engineers had created
the largest enclosed room

of any religious
building in the world,

covering an incredible
50,000 square feet.

A structure and setting
worthy of the gods,

the Hypostyle hall
was the greatest feat

of roof engineering
in the ancient world.

In recent times, engineers
have constructed the world's

most complex roof for a
very different purpose.

In the Ukraine in 1986,

one of Chernobyl's
reactors exploded.

The world's worst
nuclear disaster.

The blast blew off part
of the power plant's roof

sending plumes of radioactive
material into the air.

To stop it leaking
deadly radiation,

engineers needed to
get a new roof in place

and seal up the whole structure.

But after just five minutes
exposure to the radiation,

a worker might have
only a few days to live.

How could it be done?

Teams worked in relays
to try and lock in

the radioactive materials,

assembling a massive covering
of concrete and steel,

but these repairs
were made in haste.

10 years later, radiation
levels had risen again

and the whole structure
was in danger of collapse.

It called for a colossal
engineering solution.

Scientists came up with the idea

of constructing a
giant steel arch called

the New Safe Confinement
weighing over 35,000 tons.

It was the largest movable

land-based structure
ever attempted,

but this Goliath had to be
engineered to perfection.

Its frame, a huge
lattice construction

of tubular steel units

supported by two
longitudinal concrete beams,

strong enough to
withstand tornadoes,

earthquakes, and
extreme temperatures.

- The Chernobyl containment
system is astonishing really,

the cover itself
has to deal with

some really extraordinary
circumstances

to do with radiation

and so the materials they
use are specially chosen.

- [Greg] The structure
also protects

against damage from within.

- In the arch, you've got the
tubular steel construction

that's coated in
polycarbonate panels

to protect against
that radiation damage.

- [Greg] In November 2016,
six years after work began,

the New Safe Confinement
was rolled into position.

Thankfully it worked.

At 843 feet long
and 357 feet high,

it completely seals
in Chernobyl's toxic
radioactive ruins.

A giant protective
shield built to last

for the next 100 years.

Ancient engineers also designed
their structures to last.

Nowhere more so than in
a civilization emerging

in the seventh century BC

along the Northern coast
of the Mediterranean Sea,

Ancient Greece.

- The Greeks took temples
to a whole new level

building these huge structures.

- The Greek temple
form is one was shared

across the Mediterranean.

And it clearly is
symbolically significant,

as well as being
architecturally very impressive.

- [Greg] The Greeks
embraced Egyptian ideas

of size and impact
in their own temples,

incorporating columns,

as well as posts and
lintels in their designs.

But while the Egyptians
built their temples

for a select few to
see from the inside,

Greek temples were constructed

to be admired by everyone
from the outside.

- Greek temples are made
for the exterior view.

They are made for us to look at

from the outside,
not from the inside.

So light would have been
fundamental in every way

to how they're built
and why they were built.

- [Greg] This change called

for a new approach
to engineering.

The Greeks believed
that the secret

to making a great building
lay in mathematics.

They sought refinement
and perfection,

carefully designing and
measuring their temples,

making sure all angles,
shapes and sizes were exact.

Greek engineers work
to set proportions,

sticking to strict column
height to diameter ratios.

Stones were carved
with utmost accuracy

and tightly locked together,
enhancing the beauty

and structural stability
of their designs.

Their meticulous mathematics
enabled engineering advances

and the construction of temples
unlike any that came before.

- The Greek temples
were very distinctive,

you couldn't miss
them if you saw them.

- [Greg] Their
greatest accomplishment
still stands today,

the Parthenon.

- It is really the
apogee, it's the height

of temple construction
in the classical period.

- [Greg] Sitting high
atop a rocky outcrop

above the city of Athens.

- The intricate detail, the
quality of the carvings,

and the sheer scale of
this extraordinary temple.

- [Greg] Unprecedented in
both quality and quantity

of architectural sculpture.

- It's a statement
of perfection, it's
a statement of power,

and it's a statement
of huge wealth.

- [Greg] The Parthenon was
dedicated to the goddess Athena,

patron of the city of Athens.

- The Parthenon really is

the pinnacle of
Greek construction.

It celebrates everything
the Greeks believed in.

- [Greg] But such a
gargantuan building project

would demand
engineering excellence.

The first challenge
was to acquire

a material worthy of a goddess.

- What was used to
build the Parthenon

was the finest marble in Greece

and this is very
carefully selected.

- [Greg] This would be the
largest building in the world

to be built entirely of marble,

calling for an
estimated 13,400 blocks

weighing roughly 30,000 tons.

- It required a lot of labor.

It was a massive project
that really required

a tremendous wealth
for the city of Athens.

- [Greg] Historians estimate
the Parthenon cost the city

as much as 800 silver
talents, a vast sum

equivalent to around $16
million in the 21st century.

To the Athenians, it seemed
justified at any price,

an icon of perfection,

but this marvel isn't as
neatly symmetrical as it seems.

Its structure contains
an engineering secret.

- Well, one of the
things that is baffling

about the Parthenon is the fact

that it's got all
these imperfections.

- [Greg] Subtle curves make
each piece of the temple unique

varying by fractions of an inch.

These tiny discrepancies
were no mistake

on the part of Greek engineers.

- If you had all sorts
of straight lines there,

it would look a little bit off.

The columns would
look a little chubby.

The base would look like
it sags in the middle.

- [Greg] To create the
appearance of perfection,

the ancient Greeks came up

with engineering
to trick the eye.

They incorporated these almost
imperceptible adjustments

throughout the temple,

creating the illusion
of straight lines.

Each of the 46 columns has
a gently curving profile

and leans inward.

Engineers even raised
the temple floor slightly

in the center, from a distance,

giving the impression of
a completely flat surface.

- When you look at the building,

it actually takes out some
of the optical effects

of having curved
eyeballs and perspective

to give an impression of an even

straighter building then is
real, which I found amazing.

- [Greg] The
Parthenon's perfection

is a brilliant
engineering illusion

and these intricate refinements

required exceptional precision.

A level of accuracy
challenging to achieve

even in the modern era.

Modern engineers still rely
on mathematical principles

first laid down by the Greeks,

as they attempt their
own optical illusions

in buildings across the globe.

Opened in 2016, the MahaNakhon
Tower was recognized

as the tallest
building in Thailand,

but its unusual
appearance drew attention.

- Sometimes you look
at it and wonder

should that be standing up?

- A pixilated ribbon
swirls around the exterior,

peeling back at surface
to expose an inner layer.

- Even as an engineer,
when you look at it

it looks like it could
fall down at any moment.

It's just a
masterpiece of design.

- [Greg] However, this design
created a huge challenge

for engineers to
provide stability

able to resist lateral loads
from wind or earthquakes.

The tower is built
around a central wall

of reinforced concrete,

12 mega columns surround
the core along its height,

supporting unbalanced
gravity loads created

by the layout of
the higher floors.

This ingenious engineering

made the structure's
unique form possible.

A modern variation

on the Parthenon's
ultimate optical illusion.

Greek mathematics had
taken ancient engineering

to a new level,

but one ancient civilization
would surpass even them,

the Romans.

Developing radical new
forms for their temples,

incorporating bold ideas
never previously seen.

- Architecture in
the Roman times

was like nothing
that had come before.

- [Greg] But Rome needed

entirely new
construction techniques

and the engineering
breakthroughs

that would make them possible.

- The Romans adopted a number
of new engineering techniques

that were different
from other cultures

around the Mediterranean

and it made the interiors as
impressive as the exterior.

- [Greg] They created
huge open rooms,

not only to house vast statues,

but also to store temple
equipment and offerings.

- The Greeks, for example,
were creating a large hall,

you would see a lot more
columns peppering the space

compared to the
Roman equivalent.

- [Greg] Roman engineers
developed new forms

for their temples,
constructing a multitude

of different structures
across the empire.

But one marvel was the
most visionary of them all,

the Pantheon.

Even today, almost 2000
years after its construction,

it remains one of the world's
most breathtaking structures.

- It's an amazing survivor
of the ancient world.

- [Greg] Believed to be a temple
dedicated to all Roman gods

with engineering
features more ambitious

than seen in any
building before.

- In my mind, the Pantheon is

the most extraordinary
building in the ancient world.

It reaches the height of
architectural brilliant.

- [Greg] The Pantheon's
claim to fame

stems from its mighty dome,

entirely unsupported unlike
anything Rome had seen before.

- It is still an
engineering wonder.

The dome is still
the single largest

non-reinforced concrete
dome in the world.

It's never been surpassed.

- [Greg] Covering
a span of 142 feet,

it was twice the size
of any dome yet built.

- The size of the
dome is extraordinary

and the fact that
they could build it

in a way that meant it
did not need reinforcement

is quite a feat of engineering.

- [Greg] A landmark achievement,

but constructing this
architectural wonder

would prove to be one of
the greatest challenges

Rome's engineers ever faced.

- When you're building a dome,

you have to think about
how to make it light

and reduce the
pressure on itself

and how you're going
to construct it

without it collapsing
under itself.

- [Greg] How could such
forces be controlled?

- The dome of the Pantheon
was a real challenge

to construct, but using a
number of innovative techniques,

they were able to create
this huge structure.

- [Greg] Firstly, in
anticipation of the
weight of the dome,

engineers built within
gigantic buttress-like walls

nowhere less than 20 feet thick.

They also reduced the
weight of the dome itself

by punching out large square
panels called coffers.

- The Romans also ensured
that they kept the strength

of the dome with thicker
sections at the bottom,

but then gradually getting
thinner towards the top

to reduce the weight and
the pressure on the dome.

- [Greg] And at the summit, a
finishing touch, the Oculus.

A 27 foot wide skylight opening
directly to the heavens.

- The Oculus also helped
to reduce the weight

because it just simply
took the material away.

- [Greg] It allowed daylight
to pour into the interior,

illuminating its beauty,

but the final secret to
this engineering feat

lies in a material only
recently invented, concrete.

One of the greatest Roman
engineering advances.

- It was liquid rock and that
meant they could shape it

into the most
extraordinary creations.

- [Greg] Today, concrete
is the most widely used

man-made material in the world

and continues to
create a whole new set

of building opportunities.

What begins as a bold idea
in the mind of an architect

can be realized thanks
to the versatility

and strength of concrete.

The Auditorio de Tenerife
in the Canary islands

cuts a striking figure
against the Atlantic Ocean.

Famous for its
white concrete arc,

the first in the
history of engineering.

The slender form of the 328
foot cantilevered wing roof

demanded a material
lighter than stone,

but stronger than timber.

By constructing a steel skeleton

and reinforced concrete shell,

the concert hall's ambitious
design was brought to life.

- You have this
giant floating shell,

which looks like
it's defying gravity,

and its construction
was only made possible

because of concrete.

- [Greg] A material often
considered ugly or dull

has proven fantastically
useful in reshaping the world.

Ancient Rome didn't
have the last word

in temple engineering.

Many Buddhist and Hindu
temples found across Asia

boast some of the most
intricate and elaborate designs

ever achieved in
the ancient world.

- Temple building
in Asia has produced

some remarkable structures
over the last 2000 or so years.

- They have a lot of details

and they often create a
very intricate carving.

- [Greg] Complex and
impressive structures

made possible thanks to
engineering ingenuity.

But one incredible structure
hidden for centuries

in the Cambodian wilderness

rewrote the history
of temples forever.

In 1860, French
naturalist Henri Mouhot

was exploring the tributaries
of the Mekong River

in search of exotic insects

when he stumbled upon
something extraordinary.

A vast complex of 900
year old stone temples

long since abandoned.

Who was responsible for these
highly advanced structures

and why build grand monuments
in such a remote spot?

Answers seemed to lie with
a mysterious ancient king.

Back in the ninth century,

an ancient civilization
rained over the area

that would today
include Cambodia

and parts of Laos,
Thailand, and Vietnam,

the Khmer empire.

- Over a thousand years
ago, the Khmer empire

was one the most powerful
forces in Southeast Asia.

In 1113 AD, a usurper king of
the Khmer named Suryavarman

seized the throne after
murdering his uncle.

To avoid being overthrown
by his enemies,

he had to establish
himself as a god-king

in the eyes of his people.

So Suryavarman began
the construction

of a majestic stone temple.

It would be dedicated to Vishnu,

but would also
help him guarantee

his own place on the
throne, Angkor Wat.

- Suryavarman built Angkor Wat

as a way of cementing
his position,

demonstrating his rights.

- [Greg] The construction of
great temples was a common way

for the Khmer kings to
display their power.

- The Khmer built well over a
thousands temples in the area.

- [Greg] But Suryavarman
wanted his masterpiece

to surpass all others.

His plan was mind
boggling in scale.

Angkor Wat would reproduce on
Earth the world of the gods,

specifically the mythical
mountain known as Mount Meru,

home of the Khmer deities.

The five peaks of Mount
Meru would be represented

by the five spires
of the temple.

- And beyond that, the moat
represents the cosmic ocean

around that as well.

You see here, the
kind of representation

of the cosmic landscape.

- [Greg] Angkor Wat would
be a heavenly complex

carved in stone found on Earth,

but Suryavarman's
workers had less

than a single
lifetime to build it.

How would such an
engineering feat be possible?

The first task was
to clear the site

amid the steamy rainforest.

- It would have been
incredibly challenging

to construct Angkor Wat's
because not only was it

in the middle of the jungle,

but it was located
in a flood plain.

- [Greg] Why did Suryavarman
choose such a location

for his temple complex,
seemingly in the
middle of nowhere?

Archeologists began to
unlock its secrets in 2007

thanks to space age engineering.

Satellites and aerial
photographs were used

to analyze 1,100 square miles
of the Cambodian landscape.

Ground sensing radar
detected subtle differences

in surface moisture
and plant growth.

A sign of architectural remains
hidden below the ground.

With this cutting
edge technology,

the team produced a detailed map

of the entire area
surrounding Angkor Wat.

What they discovered
was incredible.

The map revealed a
gigantic ancient settlement

sprawling over a vast area.

- So we're not only talking
about a very large temple,

but also a massive city.

- [Greg] The lost
city of Angkor.

- [Mark] We didn't know
how large Angkor was

for a long time,
but it was revealing

that it's actually much more
extensive than we thought.

- Angkor was one the largest

pre-industrial
cities in the world.

- [Greg] Covering
385 square miles,

an area the size of New
York City's five boroughs.

For six centuries, the city
had thrived under the Khmer.

Comprising thousands of houses,

roads, manmade
ponds, and canals,

the mighty capitol of the
largest empire of its time

home up to a million people

with Suryavarman's magnificent
temple at its heart.

But one thing continued to
puzzle the archeologists,

how did the Khmer construct
a stable city here

in heavily waterlogged soil?

Nightmarish conditions

for engineers seeking
to build in stone.

- There are also challenges
obstructing near water.

One of them is that the ground

tends to be quite
variable and quite wet,

which isn't really great
for big, heavy structures.

- [Greg] As if that wasn't
enough, the yearly monsoon rains

could be expected to
wreak further havoc.

Thankfully, the Khmer had built
more than stone structures.

The 2007 survey also revealed

hundreds of interconnected
canals, dikes, and reservoirs

operated over 460 square miles.

- The Khmer were masters
of engineering water.

- [Greg] Khmer engineers dug
channels up to 12 miles long

and more than 160 feet wide

and reservoirs covering
thousands of acres.

A complex water management
network used to store

and distribute water
throughout the area.

- Because of the water
management structure,

there was a greater
retention of the water

that might otherwise have made
the place quite waterlogged.

- [Greg] Through
the 12th century,

Suryavarman's grand temple
began to take shape.

Building materials were consumed
on an unparalleled scale,

an estimated five to 10 million

precision cut sandstone blocks,

more stone than used to build
the Great Pyramid of Giza.

Khmer engineers
achieved a close fit

with a technique
called abrasion.

- Blocks were cut to shape

and then ground against each
other to achieve a better fit,

but also to generate strong
friction between the blocks.

- [Greg] The temple then
slotted together seamlessly

without the use of
mortar or cement.

Based on knowledge of
how shapes interlocked

and exploiting
the natural weight

and friction between stones,

Khmer engineers produced
the soaring details

that make Angkor Wat famous.

Spread across more
than 400 acres,

the largest religious monument
in the world by land area,

a stunning monument to
Cambodia's golden age.

Across the ancient world,

temples showcase some of the
most spectacular engineering

in all of human history.

But in the modern world,

other buildings are
coming to rival them.

Where icons of a very
different kind are honored.

- I think there are
some similarities

between religion and sport.

And I say that
speaking as an engineer

because the structures
that you create

for both of them tend to be
quite iconic, quite distinctive,

you know, make a statement
about that city or that region.

- [Greg] Just like temples,

stadiums are places where
people gather in huge numbers,

instead of honoring the divine,

they're honoring humans, or
some might say super humans.

- People get together today
in big modern stadium here

and worship their
particularly team,

they do it in massive
communities in
astonishing buildings.

- [Greg] Built with the latest
techniques and technology

to create spectacular spaces,
massive retractable roofs,

movable seating, and
superstructures engineered

to withstand earthquakes rated
8.0 on the Richter scale.

- When designing these stadiums

how are you gonna make it
worthy of the fans passion

and energy that they
bring into this space?

Making sure that it
has unique features

that I think is really important

in terms of actually
meeting the needs

and the aspirations
of these fans.

- [Greg] These are
some of the biggest,

most advanced engineering
masterpieces of
the 21st century,

just as temples were
thousands of years before,

built for the gods
of their epoch

by engineers who can not
have known their achievements

would still be admired
thousands of years later.

Temple engineering has left
a legacy for the modern world

whether in the designs for
large imposing buildings

or in the construction
techniques used every day.

The ancients
imagination and ambition

push the boundaries
of what was possible

to create awe inspiring marvels

from the spectacular
slabs of Stonehenge

to the towering
columns of Karnak

and the grandeur of
the Pantheon stone,

enduring testaments to the
genius of ancient engineers.

[dramatic music]