All language subtitles for secrets.of.ancient.structures.s01e02.480p.web.x264.rmteam

(dramatic music)

- [Narrator] Since the
dawn of human history,

civilizations have
gazed up to the stars

to make sense of our existence.

The cyclic patterns
of celestial bodies

guiding our understanding
of ourselves

and the world around us.

The intricate carvings

etched into the sandstone
structure of Angkor Wat

tell us a story
written in the skies.

Every inch of this ancient
complex is coordinated

with the cosmic realms.

- Angkor Wat is basically a
three dimensional reflection

of the Hindu universe
in cosmology.

- [Narrator] In Mexico,
the ancient Mayan building,

a ladder to the heavens.

The pyramid of Kukulcan
is a wonder of the world

shimmering with
solar alignments.

- It's actually a pyramid
built on a pyramid,

built on a pyramid.

- [Narrator] What
secrets contained within

potentially unlock a
gateway to other dimensions?

A strange earthen mound in
Ireland curiously captures

the inaugural rays
of solstice sunlight.

- On the day of the
winter solstice, the
sun would penetrate

to the very back chamber
of the passage tomb.

- [Narrator] What
were the motives

of its mysterious architects

and how exactly did
they forge this link

between earth and sky?

(dramatic music)

(bright music)

In the light of
Cambodia's rising sun,

stands a temple
unlike any other.

Its sandstone spires seemingly
reaching the heavens above.

- Sprawling over 400
acres, Angkor Wat

is the largest religious
monument ever built.

It's truly a wonder
of the ancient world.

- One of the things
that is so striking

is how massive the
actual site is.

So there is like the
Angkor Wat temple,

but then there's all
the other temples

that are part of the
whole cultural site.

- Angkor Wat without question

is one of the great marvels
of human engineering,

but it's also a stunning
work of art decorated

with innumerable
bas-relief sculptures.

It is surrounded
by an enormous moat

in a beautiful landscape.

It is one of the
great contributions
to human engineering.

- [Narrator] Built by the
rulers of the Khmer Empire,

Angkor Wat is a relic of the
12th century, a mighty monument

to a civilization largely
reclaimed by the jungle.

It stands as a keeper of
ancient stories etched in stone

and serves as a cosmic blueprint

with divine symbolism
intricately woven

into its very foundations.

- The purpose behind
its construction was

to have it embody the cosmos.

(bright music)

- Angkor Wat is basically a
three dimensional reflection

of the Hindu universe
in cosmology.

- From its foundation
to its peak,

every element of this temple
symbolizes the higher realm.

- How were its ancient
architects able

to achieve such
detail and precision?

And why was Angkor
Wat ultimately left

to be reclaimed by nature?

- [Narrator] In the
mid 19th century

while traversing the dense
landscapes of Southeast Asia

in search of natural specimens,
French Explorer Henri Mouhot

stumbles upon a
remarkable discovery,

a massive 3.6 kilometer
stone wall guarding a series

of raised galleries

and a quintet of tall
towers, the tallest

of which stretches 65
meters into the sky.

In his writings, Mouhot
declares the temple a rival

to that of Solomon, erected
by some ancient Michelangelo

and proclaims it grander
than anything left to us

by Greece or Rome.

- He's simply awestruck
by the complex.

It affects him so
profoundly, he compares it

to the pyramids.

- Angkor Wat is quite
magical in a sense

that it's very intertwined
with the nature around it.

Over time, they have sort
of become one and the same.

There's still parts
of the complex today,

so not Angkor Wat proper,

but the surrounding complex

that give people the same vision

as the French
Explorer coming across

the temple for the first time.

So it's almost like
you're discovering parts

of this complex yourself
when you're walking

to some of the
more remote areas.

- [Narrator] Though
this age old structure

had been known to local peoples

and other foreign
visitors for centuries,

the nature of its true origins

and purpose long remained
a source of speculation.

Legends spoke of
divine architects

constructing the temple
in a single night

or giants raising
it from the earth.

However, we've since
pieced together

a more comprehensive picture

tracing the
building's foundation

to the mighty Khmer Empire
of the 12th century CE.

- The Khmer Empire was one

of the most advanced
civilizations of
the ancient world.

They were incredibly
sophisticated builders
and craftsmen,

and they profoundly shaped
the history of Southeast Asia.

They ruled for six
centuries over a vast empire

stretching from southern
China to southern Vietnam,

from Burma to the Mekong River.

- [Narrator] At its heart
lies the capital of Angkor,

a metropolis
unrivaled in its time.

Home to nearly a million
citizens at its peak,

it was once the largest
pre-industrial city on earth.

- Angkor Wat stands as one

of the few remaining
architectural marvels
of this people.

- One of the reasons why there's

so few architectural
remains of the Khmer Empire

is because of the fact

that they dedicated stone
constructions to deities

and gods versus common people,

which would live in
wooden structures

and haven't survived
the test of time.

- [Narrator] The Khmer
left few written records,

but their story is
carved in stone.

Through these
detailed bas-reliefs

and inscriptions,
historians and architects

have begun to piece
together the rise

and fall of this
formidable empire.

In the early 12th century,
King Suryavarman II ascends

to the throne commanding
what had grown

to become a powerful empire.

- His reign marked
the end of decades

of civil war and unrest.

He's an incredibly
capable ruler.

He not only expands the empire
through a mixture of warfare

and diplomacy, but
he also fosters art

and culture within its borders.

- [Narrator] By 1122
CE, at the King's order,

work begins on Angkor Wat,
a stone compound destined

to become the spiritual
epicenter of the empire.

Carved from a sandstone canvas.

- Sandstone has been used to
build everything from tools

to shelters since
prehistoric times.

It's an incredibly
durable material,

making it naturally
resistant to harsh weather.

- If we think about Cambodia

and its climate, it's very
susceptible to drought,

but also torrential monsoon,

so you're going
to need a material

that's able to
withstand both extremes.

- What makes Angkor Wat Angkor
Wat is we're able to move

five to to 10 million shaped
sandstone blocks into place.

They're each about 1.5
tons, so they're big

but not too big to slide
around using incline planes

and rolling on logs.

- [Narrator] The magnitude
of the material used

had puzzled researchers
as there are no quarries

within the immediate
vicinity of the site.

- Where did the stone come from?

If not sourced locally,

how did the 12th century
workforce transport

such heavy materials
from distant areas?

(dramatic music)

- [Narrator] Angkor
Wat is likely supplied

by quarries at the
base of Mount Kulen,

located 40 kilometers
northeast of the temple.

It's initially hypothesized

that these mammoth
stones were transported

via a circuitous route
along roads and rivers.

However, in recent
decades, satellite images

and LIDAR technology have
revealed a vast network

of ancient canals, some of
which trace a direct path

from Kulen to the
temple grounds.

- The discovery of
these canals indicates

that they may have used
them for the transport

of their building materials.

- [Narrator] Even with a canal,

enabling direct delivery from
the quarry to the jobsite

construction remained
a massive undertaking.

- Some estimates
say that there was

around 300,000 people supported

by a thousand elephants

working on the construction
of this project.

- [Narrator] The full structure

takes over three
decades to complete,

and although that might
seem like a long time

by today's standards,
it's speculated

that it would've taken
their European counterparts

of the same period centuries.

Among the myriad of
architectural wonders

scattered across Asia,
Angkor Wat stands out

in more ways than one,

starting with its
unique orientation.

- Most Khmer temples
face the east

because Hindu deities normally
sit facing the rising sun,

which is seen as a symbol
of renewal and growth.

But Angkor Wat is
oriented to the west

and this has puzzled
researchers for centuries.

- [Narrator] Though
unconventional, the
precise position

of the temple facilitates
a stunning celestial event

that occurs twice a year.

During the spring
and autumn equinoxes,

times when night and
day reach equilibrium,

the temple's central
tower aligns perfectly

with the rising sun.

- In any culture that
is building spaces

that's based on
celestial events, the
solstice, the equinox,

what we're seeing is that
they're looking upwards.

When they're looking upwards,
that's where you're dreaming,

where you're creative.

When you're actually operating

or getting things done,
you're looking downwards.

That's when you're
working with your hands.

When you manipulate the
world, you look down.

You look up, when
you're imagining

how the world is
being manipulated.

- [Narrator] The
Khmer understanding
of the cosmos seems

to be embedded in nearly
every element of Angkor Wat

and this spiritual journey
begins at its perimeter.

- The moats around Angkor Wat
are really quite impressive.

They're about a kilometer
long on each side

and about two football
pitches in widths.

When we look back at
ancient civilizations

and their success, it
actually has a lot to do

with control of water.

The most successful
societies developed canals

and water control systems not
only to irrigate their fields,

but also so that any structures

that they built remain stable
over long periods of time

and work essentially
sinking into the mud

or sinking into the ground.

- [Narrator] Given the
immense height of the temple

and the region's
volatile climate,

this moat is a
careful design choice.

Khmer engineers construct
the aquatic perimeter

to counterbalance the outward
pressure of the shifting soils

beneath the temple's foundation.

- The moat was a crucial
engineering decision

to ensure the temple's
structural resilience.

- [Narrator] Without
this imposing waterway,

the 900 year old structure
would likely have

collapsed long ago.

Yet Angkor Wat's moat
transcends mere practicality.

It also carries a profound
spiritual significance.

- The moat
surrounding Angkor Wat

represents the cosmic ocean,

a mythical body of water
that marks the edge

of the universe in
Hindu cosmology.

- [Narrator] Once
across the threshold

into this symbolic realm,

visitors are greeted by
an immense enclosure wall,

towering 4.5 meters
and stretching over
three kilometers.

Once through the gate, visitors
enter the outer enclosure,

an area that is vast and open,

designed to make you feel
small and humble in the face

of something far
greater than yourself.

As you continue along
the central path,

the journey becomes
progressively

more focused on the divine.

The main tower of Angkor
Wat rises at the heart

of the temple complex
symbolizing Mount Meru.

- In Hindu cosmology,

Mount Meru is considered
the mythical mountain

where the gods reside.

It serves as the central
axes of both the spiritual

and physical universes.

- [Narrator] The
temple comprises three
ascending terraces

of galleries each rising
higher than the last,

mimicking the arduous
trek towards the heavens.

- The labyrinth of
galleries guides visitors

into the center of
a sacred shrine.

- [Narrator] Here,
the walls come alive

with vibrant tales
from Hindu mythology,

offering a first
glimpse into the kings

and deities that inspired
this grand design.

- Everywhere you look is
an absolute masterpiece

of ancient Khmer sculpting.

(bright music)

- We know that there's hundreds

and thousands of
different craftsmen

working to carve these reliefs,

but at the end of the day, it
almost looks like it was done

by one master, just
the uniformity of it.

- The bas-reliefs
are extraordinary.

They are vivid.

They come out of the walls,

and one can imagine that
as one enters the temple

during the height of the
power of the Khmer people,

the bas-relief moving
in the shimmering light

from the candles, it would've
been very, very powerful

and mysterious.

Perhaps the most intriguing

and significant of
the bas-relief is
the enormous relief

that depicts the churning
of the ocean of milk.

Now this is one of the
most important stories

in Hindu religion and it
speaks to the forces of good

and evil collaborating
in pursuit of the
elixir of eternity,

and it's dedicated
to the god Vishnu,

the god who provided order

and the restoring of
balance in society.

- King Suryavaman II
fostered a devotion

to the Hindu god Vishnu.

This was a departure from
popular Hindu sects at the time

who predominantly worshiped
Shiva as their primary deity.

- Angkor Wat was
dedicated to Vishnu.

Now there are reasons for it

that makes sense given the king.

First of all, he was the
god of order and protection.

Secondly, the anchoring.

The westward facing orientation
is intended to convey

that idea of order

because at two times of a
year during the equinox,

it fills up with light.

Now, why is the equinox perhaps
spiritually significant?

Well, the moment of equinox

is when night and
day are equally long.

It's a time of balance
and cosmic order.

- [Narrator] During the
equinoxes, the shadow cast

by a pillar marks the
opposing end points

of this bas-relief.

During the summer
and winter solstices,

the longest and shortest
days of the year,

the same shadow
highlights the center

of this divine carving.

- Over the course of a year,

the shadow moves across
the entire bas-relief,

essentially functioning
as a calendar.

- [Narrator] The
movement of this shadow

mimics the encrypted tug of war

pendulating from side to
side throughout the year.

- The cosmology is played out

through the westward
orientation of the temple.

- Many civilizations
have drawn connections

between astronomical
observations

and their religious beliefs,
believing that in part,

their lives were governed
by the celestial.

This stems from a
basic human need

to understand the universe
and our place in it.

- [Narrator] Some
scholars suggest

that Angkor Wat is
not only a temple

dedicated to Vishnu
and cosmic order,

but was also intended to be
a tomb for its commissioner

and ruler, King's Suryavaman II.

- What was the king's true
intention for the structure?

Was it merely a temple
or was it a mausoleum?

(bright music)

- As far as we know, the
king was never buried there.

We believe that he was killed
on a battle site far away.

- [Narrator] Although King
Suryavaman II's temple

still stands, his death
precipitated the decline

of his dynasty and
the Khmer Empire.

- So not long after
Angkor Wat was built

and the king died
in battle, we think,

the Khmer regime fell

and the new power in
place was Buddhist,

and so it was converted
into a Buddhist structure.

- This is a rare example

of religious conversion in
monumental architecture.

- But 300 years later
after it was built,

Angkor Wat would be abandoned.

Now, a lot of this had to do
with catastrophic flooding,

which was in many ways a
legacy of the intricate

and sophisticated water
system that had been developed

by the people during
the 12th century.

- The extreme weather events

that occurred at Angkor Wat
overwhelmed that system.

When we desig buildings,

we base our designs on
climactic data, historic data

that our structures will
experience, its probability.

Angkor Wat was designed at
a certain period in time

for a particular experience.

In the 15th century,

there would be these extreme
monsoon seasons followed

by these extreme droughts, and
the system couldn't keep up.

- Ironically, this city's
connection to water would be one

of the reasons for its
monumental downfall.

- Angkor itself was
destroyed by flooding.

- [Narrator] Though
the temple is visited

and preserved by local monks

and Khmer people through time,

its full splendor
is not understood

by the modern Western world

until Henri Mouhot's
fortuitous encounter in 1860,

which sparks a new era

of intense study on
the structural design.

By the 1990s, evidence of an
astral motive grows stronger

as a series of researchers
identify calculations

that reflect the cosmic clock.

Using the Khmer
unit of measurement

known as the Cambodian
qubit or HNt,

experts have postulated

that the temple's
dimensions further encode

an advanced understanding
of time and space.

For example, the dimensions

of the temple's highest
terrace are believed

to equal 365 HNt,
corresponding to the number

of days in a year.

The base of the central
tower measures 91 HNt,

aligning with the 91
days that separate

a solstice from an equinox.

Additionally, within the
temple's central structure,

the distance between
each step is 12 HNt,

reflecting the 12 lunar
cycles that make up a year.

These are only a few of
the dozens of dimensions

that seem to correlate
with celestial cycles

and no doubt there are many
more still to be discovered.

- Despite centuries of studies,

Angkor Wat continues to
guard its many secrets.

- [Narrator] The
Khmer are not the only

nor even the first civilization

to achieve this celestial
union with architecture.

On the other side of the globe,

nearly 16,000 kilometers away,

another ancient structure

with hidden secrets
is similarly imbued

with solar significance.

- This pyramid appears
relatively simple
at first glance,

but in actuality it's been
found to harbor hidden chambers,

human remains,

and possibly an intended
portal to another realm.

- [Narrator] Nestled
in the lush heart

of Mexico's Yucatan
Peninsula is a city

that offers a glimpse
into a world long past.

- Chichen Itza was a
thriving metropolis.

It was famous at the time
that it was first encountered

by Europeans for being this
sophisticated urban culture.

It was the center of
Mayan culture at the time.

- [Narrator] This ruinous site

is one of the seven wanders
of the modern world,

and its centerpiece is
the pyramid of Kukulcan,

otherwise known as El Castillo.

Its simple facade guards secrets

that date back for
over a millennia.

- Not unlike the
pyramids of Egypt,

historians, archeologists
are still puzzling

to this day about the particular
function of this pyramid.

- [Narrator] Researchers
have discovered

strange numerical, visual
and even acoustic features

within the pyramid's
architecture

that seemingly linked the
structure to the Maya calendar.

- Could this have
been an observatory

or a site of
celestial ceremonies?

How do the skies above
facilitate its mystical purposes

and what other mysteries lie
beneath its stone exterior?

(dramatic music)

- Often referred to as the
Greeks of American civilization,

the Mayans were an
incredibly diverse

and advanced civilization.

- They left behind an
extraordinary legacy

in terms of monumental
architecture.

But at the time,

they were also a large
thriving economic, social

and political empire.

- These famous Mesoamerican
ruins were once home

to a lively city, founded
by Maya settlers as early

as the fifth century CE.

By the 10th century, Chichen
Itza had grown to be one

of the biggest cities
in Mayan history.

During this era,
somewhere between the 10th

and 12th centuries,

construction began on a
grand four-sided pyramid

dedicated to their feathered
serpent god, Kukulcan.

- The pyramid is dedicated

to the most powerful
of the Mayan gods.

He was a feathered
serpent kind of creature.

He embodied the cosmos.

He could move between the realms

of existence from this
world to the world

of the deities down
to the underworld.

- [Narrator] Kukulcan was one
of the most revered deities

in the Maya Pantheon,
which included

over 200 gods and goddesses.

Kukulcan was believed to
govern the cycles of the cosmos

and oversee the seasonal
rhythms of growth and decay.

- We can see that with Kukulcan
being the feathered serpent,

that there was a great
reverence on flight on the air

and the space above, this is
that divine space, the space

that they would reach up to
that they could build up to,

but could not engage
in themselves.

Because as men, we don't fly.

- [Narrator] At a
soaring 30 meters,

The temple of Kukulcan
attempted to close the gap

between humans and the heavens.

- Having been to El
Castillo in Chichen Itza,

it's really quite an
impressive pyramid.

It's situated by
itself on a plane,

so it looks very
impressive and imposing.

- [Narrator] When the Spanish
arrived in the new world

and saw this towering
fortresslike structure,

they called it El Castillo,
which means the castle.

- When the Spanish got there,
this would've been, you know,

something that's really
out of context for them.

There wouldn't be
anything in Spain

or the rest of the world
that they've been to

that would really compare to
these types of structures.

- While this monument
may appear unassuming,

you have to consider at what
time it was being constructed

and what materials
were available to them.

- The structures themselves are
made of the local limestone.

There is no other
material in the Yucatan

to use to construct, so
all of their buildings

are actually constructed

of a relatively porous
limestone material.

- [Narrator] El Castillo's
simple design is striking.

The square base
measures over 55 meters

on each symmetrical side.

Four uniform staircases
meet at the pinnacle,

a rectangular sanctuary
with a flat stone roof

that contains four entrances
and three inner rooms.

- The structure is
impressively well proportioned

from its foundation
to its temple.

So how did they achieve
such a masterful feat

with incredibly limited tools?

- El Castillo's
a stepped pyramid

where we've actually
built terraces of rock up

to produce the pyramid shape.

That's a very stable structure.

It's a very easy
construction methodology.

Again, you can use
simple incline planes

to push rocks up
ramps and place them

and then continue to
build your pyramid

as you place layer
and layer and layer.

- [Narrator] This temple
dedicated to Kukulcan

dominates the landscape.

However, many believe
this structure

to be more than just a
massive monument of worship.

- The Mayans developed a
very sophisticated approach

to astronomy that led
to the development

of these multiple calendrical
systems, which were used

to help them not only with
their religious observances,

but with organizing
the rotation of crops,

harvesting and other
economic activities.

- The Mayan calendar
has similarities

to our modern calendar, a
365 day year, for example,

but it was also a
lot more complex,

combining multiple cycles

to track time with
remarkable accuracy.

This profound comprehension

of cosmic cycles is
physically embodied

in many Maya structures,
including the
pyramid of Kukulcan.

This monument has 91
steps on all four sides,

and when added together with
a temple landing on top,

these equal 365, one step
for each day of the year.

91 is also the number of days

between each annual quarter
marked by the equinoxes

and solstices,

and each side of the structure
has 52 decorative panels,

which is the exact number

of years in the
Mayan calendar cycle.

- In essence,

this pyramid embodies the
Mayan calendar itself.

- But what was the
ultimate purpose

for this cosmic coordination?

Could aligning
their architecture

with the eternal coil of time,

facilitate a deeper
connection with their deities?

- [Narrator] The
meticulous design matched

with the porous properties
at the site's limestone slabs

give rise to a
fascinating occurrence

at the foot of the pyramid.

- When you clap your hands
at the base of the pyramid,

the sound bounces off
different stone surfaces.

(hands clapping)

And it almost mimics
the chirp of a bird.

- [Narrator] This fleeting
echo strikingly resembles

the warble of the quetzal bird.

(quetzal bird chirping)

- This is a sacred bird that
still exists to this day.

Its distinctive look of green
feathers with a red body.

It evoked for them similar
elements to the image

of the feathered
serpent deity, Kukulcan.

- Was this effect intentional?

How could the Maya
have engineered such
an acoustic marvel?

- I would find it very
surprising if the echo sounds

produced by El Castillo
were intentional.

I think it would've
been very difficult

or almost impossible for the
people of that time to be able

to recognize these
audio effects.

I think it probably
arose simply as a result

of the technology used
to build the structure

and not a direct intent.

- When we think about the
marvels of this engineering,

we do have to wonder what is
intentional and what is not.

But another interesting effect

is actually the use of light.

- [Narrator] During
the equinoxes,

when day and night stand
in perfect balance,

a mysterious shadow seems to
slither down the balustrade.

- The way the light
shines in at midday,

it can look like a serpent

slowly coming down the walls.

- [Narrator] As the sun
moves through the sky,

the undulating shadow
seems to align perfectly

with a serpent skull at
the base of the steps.

It's as if Kukulcan
himself is descending

from the higher realm
to bless his worshipers.

While the pyramid's exterior
dazzles with divine symbolism,

its interior guards
an age old secret.

In the early 1900s, the
ruins of Chichen Itza

were largely covered
by dense jungle.

Much of its
architecture obscured.

In the 1920s and 30s,

explorers began
clearing the vegetation,

slowly revealing its grandeur

and intricate design,
including a hidden passage

leading to a sealed chamber.

As the door to this
room creaks open,

rare artifacts are revealed.

- One of the most
interesting discoveries

was a red jaguar throne.

The jaguar itself is associated
with power and authority.

The color red is
associated with birth

and sacrifice and death
in the Mayan tradition.

- [Narrator] Beyond
the treasures found

in what has become known
as the hall of offerings,

in an adjoining chamber,

archeologists make a
startling discovery.

- There's a room
that's now been named

the chamber of sacrifice
because they discovered in it

the presence of human bones.

- Could they have been
sacrificial offerings

and what prompted
their concealment

deep within this
ancient structure?

- [Narrator] Further
investigation reveals

that these hidden chambers,

are part of a much older pyramid

that lies beneath the
current structure.

The ancient temple dates to
between 800 CE and 1000 CE

and is approximately
17 meters high.

About half the size
of El Castillo.

The Maya often built new
temples over older ones

creating layers of history.

It's not until 2016, however,

that technological
advancements adds

yet another fascinating
layer to this tale.

When digital mapping
detects the presence

of a third building
at the site's core,

a 10 meter tall pyramid
nestled inside the other two.

Analysis has since dated
this interior pyramid

to as early as 550 CE,

approximately half
a millennia older

than the exterior we see today.

- It's actually a pyramid

built on a pyramid,
built on a pyramid.

- So essentially it's like
a Russian doll of pyramids.

- [Narrator] In capturing the
skeleton of this building,

digital mapping has also
revealed the earthen foundations

upon which it's built.

This thousand year old stone
shrine rests on a layer

of limestone bedrock
around five meters thick,

below which is
not compact earth,

but a cavernous 20 meter deep
well believed to be a cenote.

(bright music)

- The Yucatan is
really interesting

because it doesn't have
above ground water flow

and all the water actually flows

through underground
cave systems.

Periodically in the Yucatan,
some of the caves collapse

and they produce these
basically very large holes

in the ground called cenotes.

- Today, the Yucatan
Peninsula is known

as the cenote
capital of the world.

There are over 6,000 there,

and this helps us reflect
on the Itza people

who once lived there
and built the pyramid.

These cenotes were
critical reservoirs

that they relied
upon for daily use,

but they were also critical
to the performance of rituals.

- [Narrator] The
city of Chichen Itza

is built in the proximity
of four cenotes.

The most northern of these
is known as the Sacred Cenote

used by the Mayan
as a site of ritual

and sacrifice to the gods.

Over the centuries valuables
such as jade, ceramics, gold,

and even human remains have
been recovered from the depths

of this revered site.

- Any kind of crevice
like this can be a gateway

to another reality.

So these are portals

and for the Itza, these were
portals that led to Xibalba,

which is their underworld.

- [Narrator] To grasp the
significance of this discovery

and whether the Maya knew
of the cenote's existence,

researchers must
uncover an entryway

connecting the pyramid
to the cavern below.

If they succeed, it may reveal

that Kukulcan is not
merely a path of ascension

to the heavens, but also a
portal to the cross section

of dimensions, or in other
words, the axis mundi.

- The axis mundi is
a concept we find

in a lot of ancient cultures.

It's Latin for the axis of
the world, the center place

of the world where
different elements

of the cosmos come together.

Often that's sky and earth,
sometimes it's sky, earth

and underworld, but it's the
nexus that joins the universe.

- [Narrator] Could it be
that the pyramid of Kukulcan,

designed in dimensions
guided by the stars,

serves as the Mayas axis mundi?

(peaceful music)

Today over a millennia

after its original construction,
the pyramid of Kukulcan

and the surrounding city
of Chichen Itza have become

one of the most visited
destinations in the world.

- I think the pyramid
teaches us that there's still

so much we don't understand
about previous societies.

- [Narrator] Many wonder
what secrets remain enshrined

in this limestone sanctuary
and do the waters below hold

the answers previously
thought to be lost to time?

Guarding yet another cosmic
enigma on the opposite edge

of the Atlantic, an
unassuming artificial mound

rises from the earth.

Its form standing strong
for over 5,000 years.

- This amazing structure
predates Stonehenge, the temples

of ancient Greece, and
even the Pyramids of Giza.

- [Narrator] Known
today as Newgrange,

this monument retains an air
of mystery in modern times.

- The construction of Newgrange

required a sophisticated
understanding of both astronomy

and architecture, making it one
of the most remarkable feats

of the ancient world.

- [Narrator] The
architectural elements

of this ancient edifice seems
centuries ahead of their time,

yet so much remains unknown
about the neolithic visionaries

who created it.

- Who were the architects
behind this ancient wonder?

How did they make such accurate
astronomical alignments

with prehistoric tools

and what inspired them
to forge a connection

with the patterns of the sun?

(dramatic music)

- [Narrator] Situated
along the bend

In Ireland's River Boyne

is the UNESCO heritage
complex of Brú na Bóinne.

Here, a collection of
at least 90 monuments

spread across eight
square kilometers

hold the largest collection

of megalithic art
in all of Europe.

Dominating this stone spectacle
landscape is Newgrange,

a large passage tomb
sheathed by a cairn.

- A passage tomb is a burial
chamber covered by earth,

which can be accessed
by a narrow passageway.

Some are covered by
cairns, which are piles

of stones usually erected
as a memorial or marker.

These are quite common
in neolithic times

and are typically found
across Western Europe.

- [Narrator] There
are many examples

of this type of construction,

but few rival Newgrange.

Comprised of an astounding
200,000 tons of material,

the mound measures 13 meters
high and 85 meters in diameter.

- Although Newgrange
is not large to us,

in comparison to
modern structures,

to our neolithic ancestors,

it was likely enormous.

- It's massive,

and it does make you
wonder who built this?

How did they build this,

and most importantly,
why did they build it?

- [Narrator] Using
radiocarbon dating,

researchers have determined

that Newgrange was erected
in or around 3200 BCE.

- We don't actually know
a lot about the people

who constructed this complex.

They were likely farmers
who raised livestock

and grew crops in the
surrounding region.

- We think they were
an advanced society

that had a refined
knowledge of stonework

and architectural design.

- [Narrator] From
a bird's eye view,

Newgrange camouflages itself.

It's roof sowed
with green grass.

From the ground, however,

it's imposing exterior
is difficult to miss.

Faced with contrasting
cobblestones of white quartz

and black granite.

- Were these ancient
planners trying

to illuminate certain
parts of the building?

- [Narrator] The
answer to this question

might never be known.

The facade we see at
Newgrange today is the result

of a 20th century restoration.

While the cobble stones used
were discovered on site,

and there is evidence
that contrasting stones

were part of the original
design, the accuracy

of their placement
remains a topic of debate.

- The challenge
in reconstruction

is how do we recreate the facade

of a neolithic structure when
we're not even entirely sure

what it might have looked
like in its original form.

- [Narrator] The dome itself
is a pile of thousands

of water rolled pebbles
pulled from the depths

of a nearby pond,
each measuring up

to 22 centimeters in length.

The hundreds of larger slabs
that form the structure's bones

and perimeter, are predominantly
crafted from greywacke,

a type of sandstone, some
pieces measuring upwards

of four meters in length.

Yet these formidable boulders

are not so easily
sourced as the pebbles.

- The megaliths, the large
stones that were used

to build Newgrange were hauled

from maybe 50 kilometers away.

- Some theories suggest the
stones may have been transported

over land using wooden
rollers or a sled.

Then there are other theories

that they may have been
floated down the coastline

and transported by
water up the river.

Either way, this would've
been a monumental task.

- [Narrator] This
incredible task suggests

that the ancient architects
could have had a labor pool

numbering in the hundreds.

Even with so many hands,
it would've been a task

that took decades to complete.

- This was a time when metal
hadn't been fully developed,

so the workforce's
tools were made entirely

of wood, stone and bone.

- Building of it must
have taken they estimate

as long as 70 years
or more to build,

which would've been
more than one lifetime

for many of the people who
were involved in this building,

it meant that society had to
organize over the generations

to continue its work so clearly

as purpose from the
start resonated long
term in the culture

and was considered
important to complete.

- The prehistoric prestige

of this site may
have been etched

into the very stones
that support its walls.

Among the hundreds
of greywacke rocks

that line the building's
edge and interior,

75 are arranged with
some of the most cohesive

artistic compositions
of neolithic times,
the most prominent

of which can be seen on
the tomb's entry stone,

boldly marked with a large
triple spiral design.

- What do these
carvings signify?

Do they mark a boundary
between two realms?

Are they an abstract
representation of
ancient beliefs,

or could they be the
mark of a dynasty?

- Since we don't really
have any written records

of this society, we have
to rely on artifacts.

- Venturing inward,
cryptic carvings

mark the narrow walls.

- The passage into the structure
is long and claustrophobic,

and when you get to
the center of the tomb,

you're confronted
by three chambers.

- [Narrator] The entire
floor plan mimics

the shape of a cruciform.

Its most inner region
protected by a vaulted ceiling

that has remarkably
stood the test of time.

- In some ways, the passage

and the chambers within the
building are a bit rough,

but it's amazing the technology

that went into constructing
this thing in the very back

of the passage where
the chambers, the
burial chambers are.

If you look up, there's
a high corbel dome,

and that dome has not
leaked in 5,000 years,

more than 5,000 years.

- [Narrator] It's beneath
these corbel stones

in the tomb's quiet chambers,

where the mysteries of
Newgrange begin to unfold.

After thousands of years in
ruin beneath layers of earth

and vegetation,
Newgrange becomes a site

of intense intrigue when
a local farmer rediscovers

its concealed entrance in 1699.

it will be another two
and a half centuries

before the first thorough
archeological excavation

is conducted by
Michael J. O'Kelly

in the 1960s and 70s.

As his team clears the
corridor and chambers,

they uncover large
stone basins believed

to once cradle the
ashes of the dead.

Beneath the floor, a large pit
is dug in the central chamber

and a discovery is made

that confirms Newgrange is
not just a site of ceremony,

but also a tomb.

- They discovered 23
components of human remains,

which likely belonged
to five people.

Is this a collective
grave, and if so, for whom?

- [Narrator] Recent DNA analysis

of the recovered bone
samples from a neolithic man

identified as NG10
provides startling insight.

A genetic profile marks
him as the offspring

of an incestuous union within
this ancient community.

- It's likely that his
parents were siblings

or were looking at a
parent and a child.

This man may have been part of
a dynasty that was concerned

with preserving the
royal bloodline.

- [Narrator] This
practice has been observed

in other dynastic societies,

including the pharaohs
of ancient Egypt.

The earthly importance
of those buried

and the ingenuity

of the ancient architects
were further highlighted

in December, 1967.

While working in the chamber,
O' Kelly bore witness

to a surprising spectacle
firsthand, a magical glimmer

of natural light
streaming from a crevice

above the tomb's entrance.

- There was a roof box,
which was carved out

above the entrance
to the passageway,

which allowed the sun
on the winter solstice

to enter right into
the very back chamber.

- This unique display
occurs only once annually,

on the shortest day of the year.

- The winter solstice.

This is the longest period of
time that the sun is absent.

- [Narrator] Once a year at
the dawn of the winter solstice

for 17 minutes, the
sun illuminates the
heart of Newgrange,

flooding the central
alcove of ancestral ashes

before retreating to
the vast skies above.

- Greatest spectacle was
for the people inside,

deep inside the chamber,

but there was another
spectacle outside.

In Newgrange, the entranceway
was covered with white stones

that would reflect the
pink of the rising sun

on the winter solstice.

- It's astonishing to
imagine prehistoric people

planning and building
such a structure

that aligns with the stars.

- With the advent
of the Bronze Age,

Newgrange largely falls
out of use as a wave

of settlers overtake
the native population.

Yet its celestial
significance lingers on.

The new communities
erect additional menhires

around the mound,

forming what is now known
as the Great Circle.

Continuing the interplay
of structure and sun,

it casts shadows
across the site.

The shade of its tallest
pillar, touching the middle

of the famously
carved entry curve

on the day of the
winter solstice.

(dramatic music)

- In Britain, we're famous
for our stone circles,

and Stonehenge is always
the number one visited site,

but it's not just
about Stonehenge.

There are so many other
sites that predate it.

And Newgrange is a
fantastic example.

- [Narrator] Due to the gradual
shifting of Earth's axis,

our astronomical clock
runs four minutes faster

than that of Newgrange's
neolithic engineers.

Yet still, people
visit every year

to watch the solstice
sunrise herald the dawn

of a new phase.

From the haunting neolithic
stone monuments of Ireland

to the awe-inspiring
Mesoamerican pyramids of Mexico

and the breathtakingly
ornate temples of Cambodia,

these ancient wonders
stand through time

as architectural
reflections of the cosmos.

Though modern
investigations have begun

to unravel their mysteries,

countless secrets remain
veiled in the midst of time,

just waiting for the bold

and curious to uncover even
more of the hidden secrets

of these ancient structures.

(dramatic music begins)

(dramatic music continues)

(dramatic music ends)