All language subtitles for secrets.of.ancient.structures.s01e05.480p.web.x264.rmteam

(eerie dramatic music)

- [Narrator] Across the globe,

ancient architectural
marvels stand as testaments

to human ingenuity.

However, within the
stunning craftsmanship

of some of these structures,
sinister whispers linger.

- People see something
that is so majestic,

so perfect, so beautiful
that they don't believe

it could have been
created by human hands.

- [Narrator] In the
Andean heights of Peru,

a colossal stone complex
defies explanation.

Its seemingly impenetrable walls

stunning 16th-century
conquerors.

- Why did the Spanish
believe the Inca

called on dark forces
to build their fortress?

- [Narrator] Deep in
the arid landscape

of Rajasthan, India,
the mesmerizing geometry

of an ancient stepwell plunges
13 stories into the earth.

Its intricate design
seems almost otherworldly.

- King Chanda is trying
to save his kingdom,

so he turns to the dark arts.

- [Narrator] Did a
malevolent force perform

this architectural feat?

Rising above the
streets of Paris,

the Gothic spires
of a famed cathedral

have long echoed tales
of demonic pacts.

- This is a bastion of
the Christian faith.

Demons will want
to play with it.

- [Narrator] What
secrets lie hidden

in its elaborate designs?

Exploring these
architectural wonders

uncovers the fine line between
genius and the supernatural.

- It seemed like magic,

and it's not that
much of a leap to go,

"The devil was involved."

- [Narrator] Could it be true?

Or do the real answers lie
in forgotten human knowledge?

(dramatic music)
(air whooshing)

(playful music)

High in the Andean mountains,

perched above the
Peruvian city of Cusco,

lies Sacsayhuaman, a
massive stone complex

that has baffled
experts for centuries.

- The true purpose of
this colossal structure

remains one of the greatest
mysteries of Inca archeology.

Its layout hints at a
level of sophistication

that we're only
beginning to understand.

- [Narrator] With
zigzagging walls

that stretch for
hundreds of meters,

Sacsayhuaman's cryptic design
speaks to a grand purpose.

- Commonly, it was believed
that this was a fortress,

and that makes sense
when you consider

its defensive walls
and strategic location.

- [Narrator] But Sacsayhuaman's
mysteries run deeper

than its imposing walls.

Below its foundation is a
rumored labyrinth of tunnels,

potentially guarding
ancient secrets

and a haunted passage
to the underworld.

- Was this primarily
a military fortress

or a religious center,

or something else entirely?

- [Narrator] When Spanish
conquistadors arrived in Cusco

in the 16th century,
they were bewildered

by the sight of Sacsayhuaman.

- It's hard to imagine what
was going through the minds

of the Spanish conquistadors

the first time they set
eyes on Sacsayhuaman.

- Well, the first
sight of the fortress

must have been awe-inspiring,

it must have been intimidating.

- They had no frame of reference

for what they were seeing.

In some ways, the
engineering met

or even exceeded what was
possible back in Europe.

- They can't believe that it
was constructed by the Incas

because they saw them as
backward and uncivilized.

So in their mind,

they couldn't possibly
build something

as magnificent and
sophisticated as this fortress.

They swiftly attribute
its construction

to demonic forces.

(eerie dramatic music)

- [Narrator] Nearly a century

before the conquistadors'
arrival in Cusco,

Pachacuti Inca Yupanqui,
the ninth Sapa Inca,

begins the transformation
of the kingdom of Cusco

into the mighty Inca Empire,

the largest pre-Columbian
empire in the Americas.

Pachacuti is a
brilliant strategist.

During his reign,
from 1438 to 1471 CE,

he expands Inca territory
across western South America

through conquest and diplomacy,

and oversees massive
construction projects,

including Machu Picchu
and Sacsayhuaman,

marking the beginning of the
Inca Empire's Golden Age.

Cusco serves as the
capital of the Incan Empire

until the Spanish conquistadors
arrive in the 16th century,

an event that would be the
catalyst for a bloody battle.

- It's November 1533,

Francisco Pizarro
and his conquistadors

have arrived in Cusco.

This moment marks
the culmination

of a decade of Spanish
aggression in the Americas.

In 1521, Hernan
Cortes had conquered

the Aztec Empire for Spain.

Now, Francisco
Pizarro seemed poised

to do the same to the Incas.

- [Narrator] The Spanish are
initially welcomed in Cusco.

Earlier that year,
Pizarro's forces

had captured and executed
the Inca emperor, Atahualpa,

and installed the young
Manco Inca as a puppet ruler.

- But things started to
go bad shortly thereafter,

and tensions began to rise.

The Spanish began
to strip the city

of all of its gold and silver.

They looted the sacred
buildings of the city,

and all of this reached
the breaking point.

In 1536, Manco Inca
led a rebellion

against the Spanish
conquistadors,

culminating in the
siege of Cusco.

- [Narrator] Sacsayhuaman's
role in the siege

is a crucial one.

Its position overlooking Cusco

makes it an ideal spot
as the headquarters

for the 200,000 warriors
Manco has assembled.

- For the Spanish, getting
control of Sacsayhuaman

is suddenly now a
strategic objective.

(dramatic music)

- [Narrator] In May of 1536,

a force of 50 cavalry

and 120 Spanish infantry
stormed the complex.

A bloody battle ensues,

but the Spanish
eventually succeed

in capturing Sacsayhuaman.

This victory serves
as a pivotal moment

in their efforts to
break the siege of Cusco.

- In the chaos that followed,

many Inca warriors threw
themselves from the walls,

death being preferable to
being captured by the Spanish.

So it's interesting to ask

what these events can tell us

about the intended
use of Sacsayhuaman.

Was it actually intended
to be a fortress,

or was it just being used
as one out of necessity?

- New evidence
suggests the structure

may have served a much
more practical purpose.

- [Narrator] In 2008,
archeologists made

a groundbreaking discovery,

suggesting a more complex
role in Inca society,

one that may transcend its
use as a simple fortress.

- They uncover the ruins
of an ancient temple

near the site of Sacsayhuaman.

- [Narrator] The
temple's interior

reveals a connection
to the dead,

a series of
intriguing structures

that point to sophisticated
funerary practices.

- Within this temple,

they find 11 enclosures
of varying sizes.

The configuration and
contents of these chambers

strongly suggest its
use for mummy burials.

- These mummification
rituals were very important,

very significant
in Inca culture.

Clearly, they had
an understanding

that it was important
to preserve the body

for passage to the afterlife.

- [Narrator] While the
archeological evidence suggests

that the site's origins
may stretch back

even further than the Incas,

it is believed that the
Inca significantly expanded

and developed the structure.

The presence of this temple

and its secret
funerary enclosures

may hint at its role in
connecting the human realm

to that which lies beyond.

- Could other undiscovered
structures in this area

help further expand our
knowledge of this site?

Or does the truth lie somewhere

within the mysterious
patterns of the walls?

- [Narrator] The
design of Sacsayhuaman

seems to be heavily influenced

by Incan religious beliefs,

and their tether
to other realms.

- Inca religion was
intimately tied to cosmology,

with their belief system
centering on celestial deities.

- [Narrator] During his
reign in the 15th century,

Pachacuti elevates
the sun god, Inti,

to supreme status, reshaping
the state religion.

- When people can't explain
what's happening around them,

or they see the
forces of nature,

they often turn them into
spiritual beings or entities.

And so within this mysticism,

we find that there are sun gods

repeated over and
over and over again.

The sun was the giver of life.

It also marked the seasons.

In the Incan culture,
that was Inti.

- [Narrator] It's been
theorized that Sacsayhuaman

was dedicated to the
worship of this sun god.

And many elements
of its design hint

at its mystical connections.

- The walls form this very
distinct zigzagging pattern.

This angular shape creates

a series of sharp
turns and recesses.

- [Narrator] Some suggest
the design resembles

the head of a puma,

a sacred animal
in Inca mythology,

with the city of Cusco
forming the body.

- They had a complex
understanding of the cosmos.

They recognized three realms,

and each of them were tied
with significant creatures.

The underworld was
associated with the serpent,

the earthly realm with the puma,

and the heavens with the condor.

- [Narrator] These three realms

and the cryptic language
of the stars above

often govern the ancient Inca
rituals and sacred sites.

- Many ancient civilizations
actually put spiritual values

and powers into the animals
that were around them.

They've anthropomorphized
the animals themselves

to place a spiritual
lead within that realm.

- [Narrator] Sacsayhuaman's
position as the puma's head

emphasizes its importance

in connecting the earthly
and spiritual realms.

But perhaps even more intriguing

is the theory that its
layout incorporates

sophisticated
astronomical alignments,

potentially encoding
ancient knowledge.

Researchers have identified
astronomical values

in both the pattern
of its zigzag walls

and in the angles of the
wall stones themselves,

which could indicate the
alignment of the moon,

Earth, and sun at a given time,

and help predict lunar
and solar eclipses.

Similar patterns found at
ancient sites worldwide

raise intriguing questions
about a shared knowledge

spanning continents
and millennia.

This discovery
could revolutionize

our understanding of ancient
civilizations' capabilities.

But would the Inca
really have had

the engineering foresight

to build such a grand complex

in the shape of a puma's head,

or to build complex
astronomical values

into its very walls?

- We often wonder how
the ancients accomplished

what they did.

But they knew a lot more
than we give them credit for.

- The Inca people were amazing

at developing technology.

They built incredible
structures,

they domesticated llamas
and alpacas and guinea pigs.

They had terraced agriculture.

They had water control.

This society was
very, very innovative

from a technological
point of view.

- [Narrator] While
a conclusive answer

to its original purpose
may continue to evade us,

the stones of
Sacsayhuaman themselves

hold their own secrets,

hinting at a mastery
of construction

that continues to challenge
mortal comprehension.

- These walls are built
with massive stones,

some of them weighing
up to 200 tons.

- [Narrator] Believing
that only demonic forces

could have built
Sacsayhuaman's amazing walls,

the Spanish attempt to take
down the entire structure,

but reportedly find
that the biggest stones

are simply too heavy to move.

- If the heaviest stones
were too large to take down,

how on Earth were they
erected in the first place?

- [Narrator] Could
this have been the work

of otherworldly forces?

- We don't know how
they built these walls,

but it's reasonable to say

that they had a good
understanding of physics,

and they perhaps harnessed
the power of levers

to move these giant boulders.

- [Narrator] It's believed
they used wooden rollers

and levers to facilitate
the movement of heavy stones

over relatively flat terrain,

and may have constructed
ramps and inclined planes

for transporting
up steep slopes.

- Where there's a
will, there's a way,

and they figured it out.

- [Narrator] It's possible
that over 20,000 workers

were involved in building
this colossal fortress,

likely including laborers

who carried out
the Herculean task

of transporting the stones
from nearby quarries,

as well as the workers
who assembled the walls.

But how did the Inca achieve

the seemingly
impossible precision

in the stonework
we still see today?

(chisel clanging)

- The Inca were
master stonemasons,

renowned for their
remarkable ability

to construct
monumental structures

that have stood
the test of time.

The strength of their empire

is often credited
to this talent.

- And they used
multiple techniques

in order to shape not
only these massive stones,

but also to create
very polished,

finely-decorated stones.

So clearly this is signs

of a very sophisticated
artisanal culture,

but also a culture in
which art and engineering

went hand in hand.

- [Narrator] Many stones
still bear the marks

of the tools used to shape them,

suggesting the use of bronze
chisels and stone hammers

to achieve the desired
shape and smoothness.

The cutting and
setting of the blocks

were so exact that
mortar was unnecessary.

- Mortar is an important piece

to the durability
of a brick wall.

If you were to build
a wall without mortar,

you would likely have some gaps.

- That's a bit problematic

because you're going to
get water flowing down

in between the rocks.

If you get freezing periods,

it's going to cause ice to form,

and when ice forms,
it creates pressure,

and causes rocks
to be pushed apart,

and basically destroys
your construction

through natural
weathering processes.

- Mortar would close those gaps

and allow for a more
airtight structure.

However, they didn't use mortar

and instead they just shaped
everything so precisely

that mortar wasn't needed.

Dry stone masonry is a
really incredible way

to construct buildings,

and we're constructing
basically a stone

that fits like a puzzle piece

into a larger part
of a building,

we're matching every stone
to the stones around it.

- [Narrator] Some believe
they used methods similar

to those used in the
building of log cabins,

called scribing and coping.

- Scribing is the act
of shaping those stones

to match the profile
of something else.

And coping is a precise cut,

sort of a carving
out of something.

- This is beneficial from
so many points of view.

It creates a very
stable structure,

but it also resists weathering.

If we're not getting
water flowing down

between our rocks 'cause
they're so tight together,

we have a much better chance

of it enduring long
periods of time

and not failing due to
normal weathering processes.

- And they are just
perfectly fit with no mortar.

There is no gap between them.

You can't even put a piece
of paper in between there.

That is incredible.

They either coped, or
carved, or cut out,

or sanded, or rounded
all of these rocks.

Each one of these
is a labor of love.

- [Narrator] But
the Inca engineers

weren't just concerned
with aesthetics.

They built with an
eye towards longevity.

- The Incan Empire is
built high in the Andes,

and the Andes are a
geologically active area.

This area has
massive earthquakes.

It's not uncommon to have
magnitude seven-plus earthquakes

in this area.

And to build structures

that have been able to
endure thousands of years

in this environment is amazing.

Where we use dry masonry,

because the stones fit
together and lock together,

they don't want to tumble
apart in an earthquake.

- And so that interlock of
all of these stones together

can resist quite a
bit of horizontal
pressure on that wall,

be it from wind, from an
impact from something,

or from soil consistently
pressing on it.

They also were thoughtful

about the configuration
of these walls,

they're in a zigzag pattern.

Each shift through that zigzag

adds lateral stability
into these walls as well.

It acts as a unit to
resist all of those forces

that it might experience.

To recognize that the
need for robustness

around lateral forces
in these ancient times

is pretty awesome.

- [Narrator] But the
mysteries of its construction

don't end at its
unshakable walls.

- Legend speaks of vast
underground networks

connecting the fortress to
other important Inca sites.

Some even claim these tunnels

stretch all the way
to Cusco's Coricancha,

the most sacred temple
of the Inca Empire.

- [Narrator] These
tunnels could have served

multiple purposes, from
storage and shelter,

to escape routes and
ritualistic spaces.

Legends persist of vast
chambers filled with gold

and precious
artifacts hidden away

from Spanish conquistadors,

though no such treasures

have been officially discovered.

And for those who dare
attempt to find it,

grave danger awaits.
(eerie dramatic music)

In the 1920s, following
the rumored disappearance

of several tunnel explorers,

all entryways were
shuttered to the public,

though many are still tempted
to venture below today.

According to some local tales,

these cursed passages
promise to kill anyone

who steps foot inside.

Could this be otherworldly
forces at work

guarding a potential
channel to the underworld?

- Tunnels and passages
come up again and again

when we talk about
ancient structures.

And a lot of this
comes to the idea that,

you know, a tunnel
is a passageway,

and it has a mystical
significance to it

because you don't know
what's on the other end.

And you can imagine that if
you travel down this tunnel,

you will leave one
realm and enter another.

- [Narrator] Could the Spanish
have seen these tunnels

as the source of
the demonic forces

they believed
built Sacsayhuaman?

- It's interesting to
reflect, as a modern person,

that descriptions of demons

creating the structure
seems foreign,

it seems unreasonable to us.

But in fact, that would
have been perfectly natural,

it would have been a
rational interpretation

for someone like Pizarro.

- There's a tendency on
the part of many conquerors

to see the people that
they were conquering

as inferior and incapable,

and being bound by the
powers of darkness.

- When we're faced
with something

we don't know how it
happened, how it was built,

or it just looks beyond
normal abilities of man,

we put it into the supernatural.

we put it onto the
side of the divine,

if it's something that
matches with our religion.

But the primitives,
the heathens,

they're the ones
that are supporting

the negative side
of the spirituality,

devils, demons, the underworld.

- Early modern people understood

that the devil was real,
the devil was present,

that the devil's function

was to create chaos,
havoc, destruction.

And so for someone like Pizarro,

encountering the Incas
would have reminded him

of the ever-present
reality of the demonic.

- So when we consider
how the Spanish minimized

and underestimated the Inca,

it's worth asking ourselves

if we don't do the
same thing sometimes

when we look at
the accomplishments

of other ancient civilizations.

(dramatic music)

- [Narrator] Halfway
across the world

lies another
architectural enigma.

Like Sacsayhuaman, its
geometry and impossible scale

whisper of origins beyond
mortal comprehension.

India, a land of ancient wonders
and rich cultural heritage,

boasts a remarkable array
of architectural marvels

that have stood
the test of time.

While iconic sites
like the Taj Mahal

often steal the spotlight,

some of India's most
tantalizing structures

continue to perplex
historians today.

(dramatic music)

Hidden in the arid
landscape of Rajasthan,

a descent into
the depths awaits,

the Chand Baori stepwell.

- This is one of the largest
and deepest stepwells in India,

reaching 13 storeys
into the earth.

- [Narrator] Chand Baori is
one of many stepwells in India

intended as a reservoir

during the region's dry spells.

But the intricate
carvings and sculptures

that adorn its walls
hint at a purpose

beyond mere water storage.

- It is not only beautiful,

but it must have required
extraordinary precision

in its design and execution.
(dramatic music)

- There's 3,500 steps in this.

You immediately recognize
the geometry in this,

the thoughtful planning
of these steps.

- These perfectly carved steps

form a mesmerizing
geometric pattern.

- Why did they choose this
specific geometric design?

Does it encode ancient
knowledge or religious beliefs?

- [Narrator] The stepwell's
precise construction

and vast scale raise
intriguing questions

about the capabilities of
its 9th century builders.

- How did these
ancient architects
achieve such precision

without modern surveying tools?

- It almost seems to defy the
limits of ancient engineering.

- [Narrator] The hands that
carved this subterranean stone

did so in worship of water.
(water sloshing)

- So much of ancient cultures
focuses around water.

For civilizations to thrive,

they need continuous
access to it.

You have to have water.

- Nowadays, we have
great access to water.

It's considered a
basic necessity,

and it's always provided to us.

But back then, in
places like India,

you had to collect the water

so there was enough
for the community.

- In particular, in
India, there are years

where you have monsoons

and you have immense
amounts of water,

and then you'll have periods
where there isn't a monsoon

and the water table will
literally change by meters.

If we're not changing
our technology

to address the
changing water table,

our civilization is
going to collapse.

So the most successful
ancient civilizations

had ways to ensure
continuous access to water.

And that's kind of
where stepwells come in.

- The stepwells were
a fascinating and
ingenious structure

designed to serve
as water reservoirs.

- The rainwater
falls from the sky

and collects in
the huge opening.

The rain then trickles
down the steps

and collects in the bottom well.

The water then seeps
through porous rock,

which replenishes the
underground water table.

- Thirst and hunger are
some of the strongest drives

that motivate people.

These are really basic drives,

and they're in some
structures of the brain

that are the oldest ones
conserved across evolution.

It's going to be a major driver

of how that society is formed

and how decisions are made.

And in this arid land,

it should be very easy to get
a large community together

to build a stepwell

because it's something
everybody can see that they,

their families, and their
descendants are going to need.

- [Narrator] While
ancient stepwells

were vital water sources in
the arid regions of India,

their role transcended
mere necessity.

- People gathered here
not only to draw water,

but to socialize, exchange news,

and even for religious purposes.

- [Narrator] The
intricately carved walls,

niches, and pavilions
served as a backdrop

for storytelling and
artistic performances,

transforming the stepwells
into vibrant hubs

of daily life and
cultural activity.

But the complexity of
Chand Baori's construction,

its sheer scale and
intricate design

has led to persistent questions
about how it was built.

And, in the absence
of clear answers,

local legends and
folklore have flourished.

- When we think of a structure

that is essential to
the survival of people,

that is also an extraordinary
work of art in and of itself,

it was so beautiful
that stories developed

around it being a
supernatural creation.

- Legend has it that King Chanda

is trying to save his
kingdom from drought.

- This king is driven
to desperation.

He turned to the dark arts.

- [Narrator] In
his darkest hour,

the king calls upon
the help of a djinn,

a supernatural entity
with malevolent powers.

The djinn agrees to
build a stepwell.

But this offer of salvation

will come at a terrible price,

the surrender of
the kingdom itself.

(dramatic music)

- Faced with an
impossible choice,

the king accepts the terms,

prioritizing his people's
survival over his own rule.

According to the tale,
this supernatural being

constructs the entire
stepwell in a single night.

- [Narrator] Then King
Chanda experienced

a fortunate twist of fate.

- In recognizing the
king's selfless act,

a saint intervenes and
basically traps the djinn

in the bowels of the stepwell,

and the kingdom is restored.

- [Narrator] Imprisoned in
the depths of this structure

for eternity, the legend
of the djinn lingers

for centuries more.

Chand Baori's intricate
design seems to defy

the limitations of its time,

leaving many to consider
the haunting possibility

that such an entity may
indeed be responsible.

However, modern archeology
has revealed hints

about its true design.

While detailed records of
Chand Baori's construction

have been lost to history,

careful examination of the
structure and others like it

can offer some insights.

- We often think
about structures

that are coming up
from the ground,

that we're creating
space above ground.

This is actually creating
a space below grade.

And that's really interesting,

it's like inverting
my whole world.

It's really cool.

- [Narrator]
Excavation likely began

with digging the central
well to reach water level.

This would have required
precise surveying

to ensure the correct
depth and width.

As the foundation was secured,

the greatest task
still loomed overhead,

carving 3,500 narrow steps

up thirteen floors
to ground level.

- This is a big structure
where people are taking

not only a lot of time
to carve those steps out,

but a lot of time to make
sure that they're exactly

the size they need to be.

- [Narrator] The perfect
symmetry of Chand Baori

implies a mastery
of mathematics,

and potentially, a
grasp of geometry

that surpasses the known
knowledge of this era.

- When you're trying to build,

essentially, an inverted
pyramid in the ground,

you need to know exactly
what your pyramid

is going to look like before
you start building it.

If you start changing angles,

you don't end up with a pyramid.

You end up with something
that's very skewed

and would look aesthetically
extremely unpleasing.

- [Narrator] The uniform size

and precise angles of the steps

suggest the use of
standardized measurements

and possibly, templates.

- It takes a lot of precision
in each step that you go down

to make sure you're going to
end up where you need to be.

So you're literally measuring

within a few millimeters
in each layer.

- Everything is meticulous,

the angles, the
carving, the steps,

the pathways through.

There's just so much thought
put into the circulation

of this system and how
one would move through it.

- [Narrator] Could this
seemingly impossible perfection

be a clue that the mysterious
tale of the djinn is true?

Beyond practical function,

the design elements
of Chand Baori

also play with its
visitors' minds,

stirring a sense of awe,
and perhaps a subtle unease.

- The stepwell is really
interesting in its design

because of how it makes you
feel when you look at it.

And that's because in nature,

yes, we have rough
symmetry, right?

We've got two arms,
two legs, two eyes,

but yet things aren't
perfect in the natural world.

Here we see something that is
balanced out and symmetric,

but it's all sharp corners,
it's steps, it's lines.

The only place we
normally see lines

are off on the horizon.

We don't see them
in straight lines

in most any other places.

And because of it, it
gives this sense of awe.

It's not something
that is natural.

And therefore, we add
extra meaning to the space,

to the place itself.

- [Narrator] Incorporated
into the engineering design

of Chand Baori is an apparent
secret of ancient wisdom,

one that suggests a strategy

for mitigating the
desert's intense heat.

As you descend the
steps of Chand Baori,

you would feel the
temperature dropping,

defying the
scorching heat above.

The cooling properties of the
stepwell reveal themselves

when examining the
layers of its design.

At first glance, the
thick stone walls

appear only to serve
as structural support,

but they are actually
the first clue

to the stepwell's
cooling mechanism.

The builders chose materials
with high thermal mass,

creating a natural heat sink

that absorbs daytime heat,

and releases it slowly at night.

Further down, a noticeable
chill permeates the air.

- The stepwell maintains a
temperature of 5 to 6 degrees

cooler at its base
than at its surface.

Was this an intentional
design feature,

and if so, how did
they calculate it?

- [Narrator] The ancient
engineers seem to have tapped

into the Earth's natural
cooling properties,

using the subterranean design

to access cooler
underground layers.

The collected water itself
isn't just for drinking.

It plays a crucial role

in a natural air
conditioning system.

As water evaporates, it
cools the surrounding air,

much like our own
body's perspiration.

This natural cooling
system is amplified

by the well's unique
vertical structure,

which creates a chimney effect,

encouraging air circulation.

- By having that cooler
water source flow down

and having wind that
would blow on top,

it creates an
interesting thermodynamic

where it will stay
cooler down there.

- [Narrator] Warm air rises,

drawing cooler air from
the water surface upwards,

resulting in a constant
flow of breeze,

a certain shiver
from the depths.

- Ancient engineers
were able to create

a sophisticated
climate control system,

transforming a water
source into a cool oasis

in one of the world's
hottest regions.

- In an arid, dry land,

cold water is not something
most people get to experience.

Even the rains in the
monsoons are warm,

so it adds another level
of awe or mysticism

to the whole endeavor
and the whole structure,

that they're experiencing
something special here

that they cannot
get anywhere else.

- [Narrator] While its
design creates an oasis

in the desert heat,

its purpose extends beyond
mere physical comfort,

as evidenced by a nearby temple

that hints at the site's
deeper spiritual significance.

Just 100 meters
west of Chand Baori

stands a temple dedicated
to Harshat Mata,

the goddess of
joy and happiness.

Built between the 7th
and 7th centuries,

it's believed that this
temple formed a complex

with Chand Baori.

Pilgrims would typically
purify themselves

in the stepwell's waters

before entering the
sacred temple ground.

- Water is sacred
across many traditions,

and in Hindu, it has a
particularly special role,

not only in ritual purification,

but water was part
of the cosmos.

It was actually
binding the earthly

and the celestial
realms together.

So it was essential to
their understanding,

not only of their
lived experience,

their present life,
but the afterlife.

- [Narrator] This
connection also reveals

the stepwell's deep
spiritual significance,

further emphasized by its
intricate architectural details.

Many of the carvings
adorning Chand Baori

depict Hindu deities
and mythological scenes

and narrate sacred stories.

- These carvings
transform the stepwell

into a three-dimensional
religious text.

- [Narrator] Chand
Baori was likely used

in conjunction with the
nearby temple for centuries,

embodying the Hindu
concept of finding divinity

in the most essential
elements of life,

a tradition that has endured
for over a millennium.

While the specifics of its
construction remain elusive

and the legends of
the djinn endure,

Chand Baori's ancient ingenuity

continues to stand
the test of time.

- Today, India is turning
back to its ancient wisdom

in order to tackle the
modern water crisis.

- I think it is a
testimony to the ingenuity

of the early designers
of these stepwells

that they are now finding
purpose again today.

In this period of
climate change,

when we have increasing
drought conditions locally,

stepwells are now
being put back to work

because they are one of
the most efficient means

of ensuring the survival
of the local population.

- This revival of ancient wisdom

is testament to the fact

that these ancient stepwells

are not only relics of the past,

but potential answers
for the future.

- [Narrator] As
with Chand Baori,

the line between the
mystical and the physical

blurs at a grand
cathedral in Paris.

Legends whisper of gargoyles

that protect the cathedral
from unseen threats,

and tales of diabolical pacts

that may have shaped
its very doors.

Standing majestically
in the heart of Paris,

Notre Dame Cathedral,

completed in the
mid-13th century,

has captivated visitors
for hundreds of years.

- It stands as one
of the world's oldest

and most renowned
Gothic cathedrals.

- Notre Dame has
witnessed pivotal moments

in French history,

from the coronation
of Napoleon Bonaparte,

to the beatification
of Joan of Arc.

- [Narrator] The cathedral's
impressive dimensions,

with towers reaching
69 meters into the sky,

speak to the ambition
of its builders.

- This was a cathedral
built through the financial

and artisanal contributions
of the local population.

It was intended
to be the largest,

the most sophisticated
cathedral of its time.

So it was to be a mark of
the greatness of Paris,

as one of the largest

and most economically
successful cities

in Europe at the time.

- [Narrator] But beneath
its Gothic splendor

lie deep mysteries
of its construction.

- It's not only the
scale that amazes,

but the innovative techniques

used to achieve such heights.

- [Narrator] And the
structural mysteries

are just the beginning.

- Legend has it
that the gargoyles

are the protectors
of the church.

But are they
protecting the church

against supernatural forces
or against earthly threats?

- [Narrator] Beneath the
soaring arches of Notre Dame

lies a secret that
stretches back

to the very
foundations of Paris.

- For generations,
pilgrims and tourists

have marveled at the
Christian masterpiece

that is the Notre Dame today.

But few realize that the ground

that touches their
feet holds clues

to a much older,
grander, mysterious past.

- They find stone structures
underneath Notre Dame

that would predate
it by centuries.

- In the 1700s, they
discovered that the church

was built on the ruins of
an old Gallo-Roman temple

to Jupiter, the king
of the Roman pantheon.

- What does that tell us?

Well, first of all,
that you have a temple

to the most powerful
of the Roman gods,

suggests that this place,

the place where it's located,

has long been a site
of cultic worship,

and in particular,
a very sacred site.

- This is evidence of
the site's long history

as a place of worship.

How did a pagan temple become

one of Christianity's
most revered cathedrals?

- [Narrator] The transformation
from pagan temple

to Christian cathedral was
a centuries-long process.

- As Christianity spreads
throughout Europe,

the site undergoes a
radical metamorphosis.

- Sacred sites tended
to remain sacred sites

even when there was
a change in religion,

and so the Christians didn't
seem to have a problem

rededicating pagan holy sites

and making them
Christian holy sites.

- So we go from the pagan temple

to an early Christian church,

and that gets replaced by
another Christian church,

but it stays in
a line of descent

that eventually brings
us to Notre Dame.

- [Narrator] Emerging
from the shadows

of its pagan origins,

Notre Dame Cathedral
has defied centuries

of challenges and
natural disasters.

What architectural secrets lie

within its hallowed walls,

enabling the Gothic structure

to withstand the ravages
of time and nature?

For centuries,
Notre Dame Cathedral

has stood as a testament
to Gothic architecture.

But in 2019, a devastating
fire engulfed the cathedral,

destroying its roof
and iconic spire.

- To see a structure like
this be impacted by the fire,

it's a little heartbreaking
for a structural engineer.

I remember we turned it on
at our office and watched it.

- [Narrator] As
the smoke clears,

archeologists and historians

are given an
unprecedented opportunity

to study the inner workings
of Notre Dame's structure.

- What hidden resilience
did medieval builders embed

within the very bones
of Notre Dame Cathedral?

- [Narrator] One of the keys
to the cathedral's longevity

could be the 30
flying buttresses

that form its stone exoskeleton.

- When we start building big
structures like Notre Dame

with large, open indoor spaces,

we end up with immense roof
structures that are very heavy.

And the result forces
from those roof structures

invariably want to cause
our walls to buckle outward.

So we need to design systems
that support our walls.

And with Notre Dame,

that technology is
the flying buttress.

- The walls are quite tall,

so they're a little wobbly.

You can imagine building
a wall out of Lego.

At some point, it's
not very stable,

you can't put another
brick on top of there.

And so you need to
brace it horizontally.

And that's where the
flying buttresses come in.

They are lateral supports
at high up points

that then take those
lateral forces out,

and all the way down
into the ground.

Also, when you have
an arched roof,

that arch wants to thrust
out at its haunches.

And so the arch itself is
imposing a horizontal force.

That force goes into
the flying buttresses.

So all these things
are tied together

and they are integral
to that building.

If you do not have
the flying buttresses,

that building will collapse.

It's amazing to see this
ancient engineering,

and how they knew
this, and used arches,

which are another
really strong shape

in these flying buttresses

to make them lighter
and functional.

- [Narrator] As restoration work

on the burned cathedral begins,

a remarkable discovery is
made within its stonework,

large iron staples are revealed,

measuring up to 50
centimeters long.

These staples found
throughout the cathedral

bind stones together,
providing reinforcement

that allows it to achieve its
impressive 35 meter height

while maintaining a
light, slender appearance.

But the true breakthrough comes

when these iron
reinforcements are dated.

Radiocarbon dating reveals
they originate from the 1160s,

making Notre Dame the first
known Gothic cathedral

to use iron extensively
throughout its structure,

a feat not repeated
for about four decades.

But these iron reinforcements

aren't the only
metalwork hiding secrets

in Notre Dame's walls.

Adorning the massive western
doors of the cathedral

is intricate ironwork,

and with it, comes a legend
of devilish intrigue.

- There's so many legends

about the building
of Notre Dame,

but there's one from
the 13th century

about a young blacksmith
named Biscornet.

According to legend, he
had been commissioned

to complete the elaborate,

ornate iron doors
for the cathedral.

- [Narrator] But when the
completed doors are unveiled,

people are astounded.

- The level of craftsmanship
was unprecedented.

The intricate details and
artistry are so advanced

that it leaves
people in disbelief.

- No one believes
it could be the work

of a 13th-century blacksmith.

- [Narrator] This leads
to wild speculation.

Biscornet's work must
have been the result

of a deal made with the devil.

- Rumors begin to
circulate that Biscornet

had been found in his
workshop unconscious,

and that the iron doors

had miraculously been
completed overnight.

When it came time to open up
the doors, they were stuck.

According to legend,

it was only after the
application of holy water

that they were
able to be opened.

- Adding to the mystery,
Biscornet reportedly dies

shortly after
completing the project.

(dramatic music)

- For people at the time,

the battle between good and evil

was a real live one.

So actually, it wasn't a
huge leap of the imagination

to believe that these
beautiful iron doors

were inspired by the devil.

The story comes out

that it's supernatural
powers that did it.

And yet the minds
of the people around

turn to it not being
divine intervention,

but instead to it
being the devil.

- It's not surprising, in a way,

that a church of this grandeur

would attract demonic tales.

It is constructed as a bastion
of the Christian faith,

which means, of course,

demons will want
to play with it,

they will want to haunt it,

they will want to torment
those who go there.

So in that sense,

the fact that it's
spiritually significant

means that it will be a
obvious target of the demonic.

- [Narrator] To this day,

the legend of the
devil doors persists.

- And interestingly,
modern blacksmiths

can't actually explain how
those doors were constructed.

- [Narrator] Whether
crafted by human hands

or through more sinister means,

the devil doors continue
to hold their secrets tight

at ground level.

But perched up above,

Notre Dame's silent
sentinels stand watch.

What ancient mysteries do these
grotesque figures conceal?

- The gargoyles of
Notre Dame are iconic.

They are monstrous,

with bulging eyes
and sharp teeth.

- As a visitor, you
arrive and you look up

and you see these enormous
winged creatures perched,

looking down at you,

each with its own individual
personality and movement.

- What's striking
about these gargoyles

is the wide variety of design
in which they were made.

And yet, what unifies them

is their whimsical, fiendish,

almost devilish nature.

- These aren't just decorations.

These gargoyles have stood watch

over the cathedral
for centuries.

- There are a number of theories

about what they might
have been intended to do.

Perhaps the most popular one
is that they were protective,

that they were looking
over Notre Dame,

and its parishioners
with an eye out

to defeating any demons
that might be circling.

- Others see them as
representations of sin and vice,

lurking outside the
sanctity of the church.

- If you look beautiful,

people think you
can do no wrong,

that you are good,

that you're special
just by that looks.

And, therefore, the
flip side is also there.

If you look ugly, if
you look grotesque,

then you're a monster
and you're evil.

And that's why when we look
at these gargoyles now,

we see them as evil creatures.

- And there are so many
folklore and stories

associated with them.

One story goes that the
gargoyles come alive at night

and patrol the streets of Paris,

keeping us all safe from harm.

- Another tale suggests

that these gargoyles
aren't sculptures at all,

but monsters turned to stone
by the power of the church.

- [Narrator] The gargoyles
adorning Notre Dame today

are not medieval originals,
but 19th-century additions.

Many of the original gargoyles

fell victim to the French
Revolution's destruction

in the late 1700s.

Over the decades
following the Revolution,

the cathedral falls
into disrepair.

But it would receive
a new lease on life

thanks to French author,

Victor Hugo's 1831 novel
"Notre-Dame de Paris",

whose 1833 English translation

was known as "The
Hunchback of Notre Dame".

- Victor Hugo's novel
really raised the cathedral

in popular consciousness,

and led to a surge of interest

in restoring the cathedral
to its former glory.

- [Narrator] A renovation
under the guidance

of architect, Eugene
Viollet-le-Duc,

began in the 1840s,

and new gargoyles were crafted,

cementing Notre Dame's
status as a cultural icon,

and popularizing the
notion of gargoyles

as the cathedral's guardians.

But the true purpose
of these figures

is actually crucial
to the cathedral's
structural integrity.

- In reality, their function
is much more practical.

They serve as water spouts,

channeling rainwater away
from the building's walls

to prevent erosion.

- [Narrator] Following
the tragic fire

that swept through Notre Dame
Cathedral in April, 2019,

the gargoyles and grotesques
have come to embody

the enduring spirit of
this beloved landmark.

- When we think
about Notre Dame now,

and the fact that
it's now rebuilt,

it makes us realize that
monuments are not static.

They are constantly being remade

and repurposed and reused

by the cultures because
they cherish them,

because of their ties
to their historic past,

but also because
they're living spaces,

living histories, that are
still meaningful to them.

- [Narrator] The cathedral
reopened in December of 2024

after a nearly
five-year restoration,

that was not without
its challenges.

- Structures that
have caught on fire,

some of them aren't salvageable.

This one, though, being stone,

is far more salvageable

than a wood structure
would have been.

But in terms of the
tools and the know-how

and the knowledge,
and the ability

to rebuild something like this,

and not everybody can do that,

there's less and less people

who could build these
structures in a similar way,

with the expertise and
with the knowledge.

- While some have attributed
the marvels of Notre Dame

to supernatural evil forces,

the reality is that
Notre Dame represents

the pinnacle of human
ingenuity, skill, craftsmanship,

and the determination of
a people in their time.

The real magic of Notre Dame

is the medieval
craftsmen that made it.

(dramatic music)

- [Narrator] From the whispers
of otherworldly forces

at Sacsayhuaman, to the tales
of djinns at Chand Baori,

and the ominous devil
doors at Notre Dame,

the stories of these
architectural wonders

blur the line between
human achievement

and the supernatural.

While standing testament
to remarkable engineering,

they hint at forces
beyond our understanding.

What hidden truths

might these ancient
structures still hold,

waiting to be uncovered
by future generations?

(dramatic music)

(dramatic music continues)