Secrets of the Dead (2000–…): Season 15, Episode 5 - Teotihuacan's Lost Kings - full transcript

Teotihuacan,

a mythical ghost town

dating back 2,000 years.

Little is known about the people
who built this ancient city

in the heart of what
is today modern Mexico.

In a hundred years of
archaeological research

in Teotihuacan,

we still haven't found a ruler's grave.

Scientists trying to unlock the secrets

of Teotihuacan have
discovered a hidden tunnel

leading right to the center of the city.



I was very scared.

Who built this vast metropolis?

And why did these powerful people

seemingly vanish without a trace?

The answers lie deep underground.

Anything found beneath it must have been

of utmost importance and sacredness.

A spectacular journey into
a mysterious world, built

beneath the first
mega-city in the Americas,

where scientists will find answers

that explain the origins
of an entire civilization.

It was the biggest
adventure of my life.

"Secrets of the Dead"

was made possible in part by



the Corporation for Public Broadcasting

and by contributions
to your PBS station

from viewers like you. Thank you.

More than a hundred years

before Columbus arrives
in the new world,

the Aztecs reign over Mesoamerica

as the last great culture
before the Spanish conquest.

As they venture south,

a group of warriors makes
a stunning discovery.

Giant pyramids,

the remains of an enormous ancient city,

completely abandoned,

a ghost town.

The Aztecs are certain

only the gods could
have built this place.

They call it "Teotihuacan",

"the City of the Gods."

Nearly 700 years later,

the Aztecs? question
remains unanswered:

Who built this magnificent city?

One man believes he
has found the answer,

Mexican archaeologist
Sergio Gomez Chavez.

[Gomez speaking Spanish]

I have been working for
34 years in Teotihuacan,

and I?m about to uncover the mystery

of the city of the gods.

The city is more than 2,000 years old.

The pyramid of the moon
lies at the northern end

of the main avenue,
the street of the dead.

Towering nearby is the
pyramid of the sun,

the third-largest pyramid in the world.

Their builders left no written records,

only the ruins of their civilization.

It's easy to imagine that
the Aztecs themselves believed

that this city was created by the gods.

October 2003.

Gomez was a junior archaeologist,

his job: mapping the pyramid
of the feathered serpent,

the smallest of the 3
pyramids in Teotihuacan.

He was just walking toward
the pyramid from his quarters

to start the day's work.

It had rained a lot those days.

It was a very cold day in early October.

Suddenly, some colleagues
walked down here to tell me

that the rain had
caused a crack in front

of the pyramid of the feathered serpent.

Gomez remembers how he hurried down

to the pyramid of the feathered serpent.

After some digging, he discovers a shaft

that looks like a bottomless well.

[Gomez speaking Spanish]

When I went down the tunnel,
i felt fear rise up in me.

It was like losing control.

[panting]

I still don't understand how

I found the courage to go down there

with only a rope tied to my waist

and no clue of what was coming.

[heart beat pounding]

My heart was beating hard.

I wanted to get out of there.

[Gomez speaking Spanish]

But then there was the tunnel.

I could see on one side
that there was an opening.

[Gomez speaking Spanish]

Every archaeologist dreams
of a moment like this.

Your work is driven
by uncertain situations.

Gomez crawls into the crevice.

He can barely see two feet ahead.

[Gomez speaking Spanish]

As I moved forward,
I touched the walls.

They were very smooth,

and very quickly,
from the way they felt,

I understood.

These were not natural walls.

They were constructed by human hands.

They were part of an ancient structure.

[Gomez speaking Spanish]

We can't go further.

Sergio Gomez has reached what appears

to be a dead end.

The tunnel is filled with debris.

He wants to know what
lies beyond the rubble

and brings in a 3D laser scanner.

Hundreds of thousands of lasers

bounce off the tunnel
walls back to this device,

creating a map of what's ahead.

The 3D image shows the tunnel continuing

in a straight path...

directly to the pyramid
of the feathered serpent,

which stands at the
very center of the city.

The pyramid represents
the heart of Teotihuacan,

its central landmark.

A tunnel leading directly
underneath the pyramid

of the feathered serpent
must have some significance.

[Gomez speaking Spanish]

So I came to the conclusion

that the tunnel had been sealed

to bury something or
someone at the end of it...

directly under the pyramid.

I thought it could be a ruler or a king.

David Carballo,

professor of archaeology
at Boston university,

agrees with Gomez?s conclusion.

He has been working at
Teotihuacan for 17 years,

concentrating on the
city's living quarters.

Carballo: This is an example
of an apartment compound.

It's where people would have lived,

and it gives an idea of domestic
architecture and residential space.

Right here, we're in the central
courtyard, so rooms tend to be

organized around a courtyard.

On the walls, Carballo
finds the remains of murals

depicting gods and priests

and scenes of creation and paradise.

They are the only record the
people of Teotihuacan left,

aside from the buildings themselves.

He also discovers something
below the living quarters

that could shed light on
the tunnel under the pyramid,

ancient bones.

Burying the dead in tombs
beneath their residences

was a common ritual in Teotihuacan.

The skeletons themselves
revealed even more

about the origins of the people

who inhabited this mysterious city.

At the lab, Carballo and his colleague,

biological anthropologist
Rebecca Storey,

examine several bones.

This is an example of the burial
underneath an apartment compound

in the Tlajinga district.

It's a male skeleton.

From the artifacts
found with the remains,

the scientists theorize that
he may have been a leader

of a neighborhood on the
outskirts of the city,

but there's still more
to learn from these bones.

Storey: He died in Teotihuacan,

but one of the interesting
questions we have is,

where did he live? Was he
a Teotihuacano all his life?

And as it turns out, one of
the most exciting things

that's come up in skeletal analysis

has been the ability to test

where people lived as
children and as teenagers?

and the secret is the teeth.

The teeth form from the time

that you're a very small child
up until you are an adolescent.

And as it turns out,
once the enamel is formed,

it's permanent, nothing changes.

The drinking water that
you take up as a child,

and then gets incorporated
into your enamel,

has different isotopic
signatures, depending on where

you were geographically
and climate-wise.

And what you do is you test
the enamel of the teeth,

and you test the bone and
see if they are the same.

The results are stunning.

Storey: His teeth were tested,
and it turned out to have

a signature very
different from Teotihuacan.

Isotope tests conducted on dozens

of other remains all
yield the same results.

With this information,

Carballo and Storey conclude
that tens of thousands

of Teotihuacan?s ordinary citizens

came from other parts of Mesoamerica.

What that tells you is
that they are migrants.

Carballo now understands;

people came to Teotihuacan

because of catastrophe elsewhere.

Carballo: The eruption
of Popocatepetl volcano

in the mid-to late-first century

was what volcanologists would describe

as a VEI-6 eruption.

and for some perspective,
a historical eruption

of that magnitude went off in Indonesia

and could be heard in Australia.

A catastrophe of epic proportions.

Carballo: after the volcanic eruption,

the sky was darkened
for extended periods.

The sooting or blackening of the sky

because of the volcanic ash

would have affected
sunlight and agriculture.

This would have seemed like
an apocalyptic scenario

to people living around the volcano.

[people screaming]

Carballo: The human toll
and the magnitude

of this eruption, uh people
would have been thinking

that the gods had turned.

Settlements were destroyed.

Livestock died out.

The very air and soil became
toxic from volcanic fallout.

The people were forced to move north

as fast as they could.

They found refuge in a valley

and settled there.

Carballo: When they came to Teotihuacan,

they were leaving a place
that was probably burnt

and seemed like hell, and they
were coming to this paradise.

It was also nicely removed

from seeing the volcano, Popocatepetl,

which couldn't be seen from
the vantage of Teotihuacan.

For the refugees,

this safe location 60
miles from the volcano

must have offered a fresh start.

The mild climate and fertile ground

made it perfect for agriculture.

Here, they will ultimately build a city

unparalleled in the Americas.

Carballo: The refugees arriving

from the areas of
eruptions would have felt

like they were getting a second
chance at Teotihuacan, that here

they had the opportunity
to build a new order

and leave behind the one
that was destroyed.

Back in the tunnel,

Sergio?s team has dug their
way more than a hundred feet

closer to the pyramid
of the feathered serpent.

They have removed more than 400 tons

of soil and debris, back-breaking work.

[Speaking Spanish]

The work we do here
every day in the tunnel

comes with many dangers.

The tunnel also poses
a risk to our health;

we noticed that there is a
gas flowing inside the tunnel.

This gas, radon, can,
according to studies,

cause lung damage.

But as difficult and dangerous
as these conditions may be,

they also represent an
upside for the scientists.

Gomez: The humidity can have
the effect of preserving things.

These conditions are actually
really beneficial for us.

As they excavate the tunnel,

they find hundreds of artifacts...

mallets, chisels, hammers,

wooden tools preserved
under these special conditions.

Gomez: They are incredibly
special and unique

because more than one of these
objects has never been found

in the history of Teotihuacan before.

This is very important for us

because these objects will
allow us to backdate and learn

from what time and what
context they originated.

Analysis shows the tools were made

around 150 A.D., at exactly the time

when the main structures
above ground were also built.

[Gomez speaking Spanish]

Wooden tools like this were used

with stone hammers to dig the tunnel.

The traces are still there.

We found holes like this one here...

and here, and here is another one.

The rock in Teotihuacan
valley is volcanic.

It is extremely difficult to excavate.

For the first time, Gomez appreciates

how hard it really must have been

for the builders of
this mysterious tunnel.

Gomez: You have to
remember that back then,

they didn't have metal tools.

For this reason, wood or
processed bone were used

in the construction of the tunnel.

And then, Gomez finds something

that puts him into direct contact

with the people who
built this very tunnel...

a handprint left by one
of the ancient workers,

preserved for almost two millennia.

For a moment, Sergio can touch the past.

[Gomez speaking Spanish]

As an archaeologist, this is incredible

because it's as if I am touching
the hand of the person

who worked here 2,000 years ago.

And it's more than just the tunnel.

These people built this entire city

with their bare hands.

You have to imagine that these
are people without pack animals,

without the wheel, and this
construction is occurring

on the backs of humans
who are dumping fill

of rocks and rubble to erect

some of the largest monuments
of the ancient world.

Even more impressive,

they did it in a very
short amount of time.

An examination of the
buildings all across Teotihuacan

indicates the city was built

in just over 200 years,

without the help of basic
construction materials

or methods, more than a thousand years

before the wheel was introduced

in the Americas.

Pigment traces on the buildings

reveal something else astonishing.

Teotihuacan was a painted city.

It was full with spectacular murals,

covered in white stucco and pigments

that came from different
parts of Mexico.

The city must have been magnificent.

Colors adorned the major buildings...

a far cry from its beginnings
as a squalid refugee camp.

In the second century A.D.,

Teotihuacan was the largest

and most important
metropolis of Mesoamerica.

To David Carballo and Sergio Gomez,

it is clear the ancient
inhabitants built the city

in honor of their gods,
and one in particular,

the feathered serpent, Quetzalcoatl.

[Gomez speaking Spanish]

Carballo: There are earlier
appearances of the god

within central Mexico and
other parts of Mesoamerica,

but it's Teotihuacan where it
first really comes together

as a clear cult.

Quetzalcoatl,

as the Aztecs will call him
hundreds of years later,

is the god of creation,

the harbinger of life itself.

With his feathered collar
and rattlesnake tail,

he is half-bird, half-snake.

The ancient Teotihuacanos
installed an estimated

260 of these stone heads on the pyramid

in honor of the feathered serpent.

Clearly, the feathered serpent
was the most important god

in Teotihuacan.

But for the inhabitants,

the god of creation

was also a god that could take life.

Over the years, scientists have found

a number of hidden chambers
inside the pyramid of the moon.

The remains of sacrificial
animals were discovered

inside these chambers.

The builders must have
buried the animals alive

and constructed the pyramid around them.

They're predators, they're raptor birds,

or occasionally they'll be

animals associated with
the souls of dead warriors.

Pumas, jaguars, wolves, or coyotes.

In many cases, it's clear that
these animals went in alive,

so, for instance, some
of them have evidence

of having been in cages.

There are the remains
of the wooden beams

of the cage that were preserved.

But the builders did not
stop at animal sacrifices.

Humans were also part of the
sacrificial offerings in major pyramids.

[clamoring]

Carballo: So a lot of the
sacrificial remains have

their arms tied behind their backs,

and this suggests that
they didn't go in willingly.

Whether or not they went in
alive is another issue.

They might have been clubbed or drugged

before they went in; in other cases,

there might be an example from
the moon pyramid of having been

buried alive.

[yelling]

Carballo: The sacrificial
offerings at the temples

were acts of consecration, so
they were making space sacred

and making a new construction
phase of a pyramid

or of a temple sacred,

and that required the giving of life.

Although not all remains
show signs of trauma,

the ancient human sacrifices prove

that this was a culture
willing to commit murder

for the greater spiritual good.

Rebecca Storey examines
one of the skulls

found in the moon pyramid.

It belonged to a young man.

She explains how the
ritual was performed.

Storey: He was decapitated.
How do I know that?

He's got one of the cervical vertebrae

that's right under the head.

Those are usually found
with decapitated individuals.

The head was detached from the body

just below the first vertebra.

The bones tell her even more
about this brutal ritual.

This individual was probably killed

another way before the head was taken.

These injuries on 3 parts
of the skull are preserved.

These cuts actually aren't
the cause of death.

They would cut somebody
back here, and then here,

the mandible has cut marks on it, too,

so it means they were cutting here.

But she doesn't believe beheading

was the cause of death.

Storey: They probably
sacrificed him through the heart

because you get lots of blood,
and certainly that was

a very common way to sacrifice people.

There are pictures in Teotihuacan

of hearts on an altar,
so there? makes sense

that maybe his heart was taken.

That meant he would have
been dead by the time

they tried to take the skulls.

About 40 victims have been found

in the different layers
of the moon pyramid.

Even more bodies have been found

at the pyramid of the feathered serpent,

where Gomez?s tunnel
seems to be leading?

200 ceremonial victims

in symmetrically arranged
mass burial sites.

From a modern perspective,

human sacrifice can
seem especially cruel.

But we have to imagine
a religious system

in which there was a
strong idea of covenants,

where the gods had given and sacrificed,

and they needed to be fed,
and time itself needed

to continue going through sacrifice.

Back in the tunnel,

where the mass graves were discovered,

Gomez?s team is slowly making progress.

They have found what
appears to be a deeper pit,

more than 80 yards from
the tunnel entrance.

As they excavate the pit,

the team uncovers
something remarkable...

and immediately calls
Gomez over to have a look.

The pit contains
precious jade artifacts.

[Gomez speaking Spanish]

We found a number of chains
and extremely valuable objects.

We know they must have
been of immense value

to the Teotihuacanos because
they were brought here

from far away.

This type of jade only exists

in Guatemala,

600 miles from Teotihuacan.

[Gomez speaking Spanish]

Whoever owned these
objects must have been

of high status because they
were able to import them.

Assuming only people of high status

would own valuable objects like these,

they must have belonged
to an important person...

and the next discovery makes clear

how important they must have been.

A blade made of obsidian.

Gomez: For Teotihuacan, obsidian
played a very important role.

The rare stone blade was
sometimes used as a tool,

but most certainly
in the ritual killings.

[Gomez speaking Spanish]

This knife is an exceptional find.

It's incredibly well-made

and shows no signs that
it was ever even used.

It was put here deliberately as part

of a very important sacrifice.

The archaeologists now believe

this sacrificial blade was buried here

with the only type of
person who would wield it,

a priest.

David Carballo sets out to visit

the source of the
precious green obsidian.

He is heading to El Chico National Park,

about 30 miles north of
the ancient ghost town.

[Both speaking Spanish]

Here, he meets Alejandra Pastrana,

one of the world's leading
experts on obsidian.

Pastrana found the ancient
obsidian mine of Teotihuacan.

This is where the sacrificial
blades came from.

This is the only place in the world

where green obsidian of this quality

can be found.

[Pastrana speaking Spanish]

Here, we have obsidian fragments.

They only emerge when
lava solidifies rapidly

with a more than 10% share of water.

In its raw state, the
rock seems unimpressive,

but Pastrana knows how
to reveal its true power.

[Speaking Spanish]

Let's chip off a shard
to test the quality.

You can see how green this one is.

It's extremely sharp
when it's first detached.

Wow.

It's the sharpest material in nature.

This edge, if you looked
under high magnification,

is completely smooth,
unlike surgical steel;

you can see that it's rough
compared to obsidian.

Sharp like a scalpel,

obsidian was known as
the metal of the Americas.

Scientists have found this
valuable green obsidian

all over Mesoamerica,

as far north as Arizona

and all the way to Guatemala and Belize

in the south.

Teotihuacan controlled
the most desired material

of the Americas.

It made the city an economic powerhouse.

Meanwhile, the team
continues to excavate.

Beyond the pit, 100 yards
further into the tunnel,

they make yet another
revealing discovery,

a stash of gigantic seashells.

These shells were most
likely used as horns

during the ritual killings,

perhaps calling the
people of Teotihuacan

to watch the holy executions.

[Gomez speaking Spanish]

There are hundreds of large
shells that were placed

in the tunnel, also as an offering.

We can tell that most of them
come from the Caribbean.

They were imported to Teotihuacan

and then also just
stored inside the tunnel.

Some shells are painted with images

of holy animals, like crocodiles.

They were valuable,

and only priests would have
been able to afford them.

As the archaeologists
wonder about the shells,

they continue to find more artifacts.

The quality and sheer
mass of their findings

is an archaeological sensation.

[Gomez speaking Spanish]

We found over 40,000 objects
made with green stone,

and about 4,000 of
these objects are jade.

All of this jade comes from the area

around the river Motagua in Guatemala.

We see Teotihuacan expanding

throughout central Mexico
and into more distant places.

The city must have been very wealthy

if these rare and expensive
items were buried in the tunnel,

and this seems to be
supported by another finding.

Carballo: In the third century,

the focus of building a
Teotihuacan really changes.

It goes from these large
pyramids and monuments

to apartment compounds,
which would have housed

the population of this large city.

It appears, at the height of its power,

the leaders of Teotihuacan initiated

a huge housing program.

Even the apartments
for ordinary citizens

had remarkable amenities.

They were built of volcanic rock,

featured an interior kitchen,

and had separate bedrooms.

The apartments even had a
functioning drainage system.

Carballo: At that time,

it's one of the largest cities
in the ancient world.

Teotihuacan had a population of
over a hundred thousand people.

For a comparison, London
didn't reach that population

until the 16th century.

And the scientists have
noticed something striking.

Carballo: There's no
fortifications around it.

It sits on a valley floor, exposed,

and there's also no
evidence for any sort

of external threat ever
having attacked the city.

Further, there's no written records,

and within the art of
the city, we don't see

any clear evidence of
an external warfare.

Does that mean that Teotihuacanos lived

in absolute peace?

Not necessarily.

600 miles away,

in what is today Southern Mexico,

lies the city of Tikal,

once ruled over by the formidable Maya.

This stone stela is where

the Mayans kept an
account of their history.

Nikolai Grube,

from the university of Bonn in Germany,

is one of only a few people in the world

who can decode the Mayan writings,

and he has found something
that may also shed light

on the mystery of Teotihuacan.

On the basis of the very
detailed Maya calendar,

we can pinpoint what happened
in what time of history.

The most fascinating part
of this long inscription

is located here, in
the middle of the stela.

[reading ancient language aloud]

It begins with a date,

a date that corresponds to
the 15th of January, 378,

and according to the hieroglyphic text,

this was when foreigners

came from the west.

And most interestingly,

it's the same day the king
of Tikal "entered the water."

To enter the water is an
expression for death, so he died.

This is certainly not an accident.

The illustration seems
to depict an invasion,

a foreign army from
the west invading Tikal.

[clamoring]

They killed the Mayan king

and installed a ruler of their own.

On this side of the monument,

we see the newly inaugurated king,

Yax Nuun Ayiin,

who acceded to power in 379 A.D.

he is dressed

in a totally different way,

not in a Maya style.

In his hand, he carries a spear thrower.

And it's this particular weapon

that helps identify the invaders

and their king.

Carballo: The atlatl, or spear thrower,

would be used to project
darts or thrown spears

at a much higher velocity
than you could with your arm,

so it represents a superior
projectile technology for the time.

At this point of time,

the only civilization in Mesoamerica

which used a spear
thrower was Teotihuacan.

Therefore, we think
that Yax Nuun Ayiin came

from Teotihuacan, that
he is a Teotihuacano king

who was placed in power

by the arriving foreigners,

and he became the founder

of a new Teotihuacan-related
dynasty in the Maya lowlands.

"Yax Nuun Ayiin" means "green crocodile"

in the Mayan language.

That the Maya wrote his name down

suggests he was a powerful ruler.

The foreigners left a deep
impact on classic Maya culture.

They changed Maya architecture,

they brought in new forms of dress,

new ceramics,

forms of mural painting.

In general, the art,
all of a sudden, changed,

but it's not only the art.

The Maya also adopted one
of their conqueror's gods,

the feathered serpent,

the Teotihuacan god of creation.

The Maya call it Kukulkan.

These stairs at the famous
Mayan temples at Chichen Itza,

built more than 600
years after the invasion,

are identical to the symbols

of the feathered serpent at Teotihuacan.

Maya kings tried to draw prestige

by associating themselves with
Teotihuacan and its symbols

and this would be similar
to the Kaisers of Germany

looking to Rome as the earlier model.

I would speak of a dramatic
shift in Mesoamerican history,

as the conquest of
Tikal probably is part

of expansion polity,

which extended the limits

of Teotihuacan power as far north

as the modern border

between Mexico and the United States

and to the south, towards Honduras.

What if the green crocodile,

the Teotihuacan leader
who subjugated the Maya,

was an expansive ruler,

like Alexander the Great or Napoleon?

Could Sergio Gomez and his team

have discovered his grave

at the end of the tunnel?

It's an exciting possibility.

Now, the tunnel grows very narrow.

Gomez sends in a robot
to explore what lies ahead.

[Speaking Spanish]

We've discovered that
the tunnel descends

at least 3 meters from the
level from which we started.

We don't know what it is

because we suddenly had
a wall in front of us,

which led down.

The archaeologists proceed slowly.

[Gomez speaking Spanish]

At first, we felt that the geo-radar

would show us a room
at the end of the tunnel.

But when the robot got in there,

we found out that there was
actually not just one room,

but 3 large areas.

So we know now that 3 main chambers

are located at the end of the tunnel.

3 chambers, each more than
a hundred square feet wide,

form a cross, as if to mark something

directly underneath the pyramid.

[Gomez speaking Spanish]

The location of these
3 chambers lines up

exactly with the vertical axis

of the pyramid of the feathered serpent.

We don't understand how they managed

to calculate the exact point
where the axis lines up

with the pyramid, located
several meters above.

The chambers at the
end of the tunnel lie

under the geographical
center of Teotihuacan,

and Gomez has a theory about why.

This is where the underworld
and the heavens meet.

The workers start excavating
the first chamber

and, after removing
only a foot of debris,

make yet another stunning discovery.

A statue, in perfect condition.

[Gomez speaking Spanish]

Because we recognize the clothing,

we see that the statue
clearly represents a woman.

This sculpture symbolizes
a very important element,

and it's very likely that it
was connected with fertility.

And then they find another statue.

[Speaking Spanish]

Right here, next to
the female sculpture,

we have also found
a smaller male sculpture.

And on every side of the two,
there is another woman,

and they all seem to
point back to the middle.

This center is the same
point that connects exactly

with the imaginary path between
the underworld and heaven.

So I believe that these
sculptures had been placed here

to act as watchmen and guard
this particular place.

Gomez thinks that the 4
guardians must have been

protecting something
important in the tunnel.

He is intrigued that their
placement seems to align

their gazes in such a way
that their visual axis

intersects right in the
very center of the room.

Continuing their excavation,

the archaeologists find more artifacts.

Gomez is certain they must have
been some kind of offering,

but the team reaches the bottom
before finding anything else.

[Speaking Spanish]

We imagined that we'd
find a person's remains.

We thought it would be the
burial place of some ruler.

We were surprised when we found nothing.

Gomez and his team must
face the disappointment...

and yet, he cannot believe
this intricately designed space

under the center of the
city holds no meaning.

He and David Carballo return
to the chamber one more time

to see if they might have
missed something.

When they inspect the walls,

they notice what looks
like a water line.

[Speaking Spanish]

[Gomez speaking Spanish]

I think that the Teotihuacanos dug

this last stretch of the tunnel deeper

to make sure that it was
permanently filled with water.

But why would the ancient builders dig

below the groundwater level on purpose

and cause the lower
chamber to fill with water,

just as a well might?

The groundwater would have
seeped into this lower chamber,

creating an artificial underground lake.

Why would they have put
a lake directly under

the pyramid of the feathered serpent,

the god of creation?

Gomez remembers the mural
found in the apartments,

and an idea begins to form.

[Gomez speaking Spanish]

The mural shows an image of a mountain.

Emerging from the inside is
the water from the underworld.

The underworld is a
place full of riches,

a place of abundance and fertility.

This painting reminds Gomez

of what he has seen in the tunnel.

Could he be looking at a representation

of how the Teotihuacanos believe

the world was created?

[Speaking Spanish]

The pyramid of the feathered serpent
could represent the holy mountain,

and the tunnel could
stand for the underworld

from which the water flows up.

The idea may not be so far-fetched.

In many other ancient cultures,

pyramids were built
to represent mountains.

If Gomez is right,

the pyramid of the feathered serpent
represents the holy mountain...

and the underground lake
symbolizes the origin of life,

springing eternally from
underneath the pyramid.

[Speaking Spanish]

David, come here.

Gomez has found traces
of a metallic substance

applied to the tunnel walls.

It's pyrite, the mineral
known as "fool's gold."

It is impressive.

It looks like almost the entire
tunnel, the walls and ceiling,

were covered with this
metallic mineral powder.

Imagine the tunnel
in the light of torches,

covered with all this
metallic mineral powder.

It really must have been incredible.

It must have looked
like a starlit night.

It is indeed a portrayal
of their cosmos.

[Speaking Spanish]

Now we can begin to understand

the meaning and significance.

Mm-hmm.

For Gomez,

the pieces of the puzzle
finally come together.

The artifacts were offerings,

not only to the gods of creation,

but to the very source of life itself,

all in this magnificent model

located 60 feet underground.

Gomez imagines this is where

the priests of Teotihuacan
made their offerings.

This chamber represents their idea

of how life began.

This holy lake,

with its illuminated sky,

was used as a stage for
their dramatic rituals.

[Speaking Spanish]

The Teotihuacanos created the underworld

in these tunnels and the
chamber under the pyramid.

But here, instead of seeing
the underworld as a place

of death, it's actually seen
as a place of creation.

The Teotihuacanos erected their
pyramids in honor of the gods,

and they built an underground replica
of their cosmos to worship them.

But then,

the gods turned against
the people once again,

and once again,

a volcano seems to control
the fate of Teotihuacan.

In 536 A.D.,

the Ilopango, a super volcano,

erupts in El Salvador.

Another volcanic winter.

Even though it was
hundreds of miles away,

the smoke and ash would
have hidden the sun for days.

With the harvests ruined,
the city could no longer

feed its people.

Carballo: What we see archaeologically

next to the major temples
of the building and buildings

of the street of the dead is,
around the mid-to late-sixth century,

there was a massive-scale
burning event...

and there's traces that are?
can be registered

both on the architecture itself
and on perishable materials

such as the roof beams that fell
down to the floor of structures.

To Carballo,

it doesn't look like an
attack from the outside.

There is no damage in
the outer districts.

There was the internal
and very targeted burning

of the city's center.

Over a hundred buildings
around the street of the dead

were burned.

The end result could have
been something like revolt.

Carballo thinks the
people might have rejected

the gods who failed them yet again,

and they set the sacred
heart of their city ablaze.

Soon after, the city was deserted.

The state had collapsed,

the city was no longer
an impressive place,

and then it moved
into the realm of myth.

The economic and political
powerhouse no longer existed,

but its legacy has
lived on for centuries.

Grube: Even after the
collapse of Teotihuacan,

the Maya continued to venerate

Teotihuacan gods in their religion.

So did the Aztecs,

until the time of the Spanish conquest,

hundreds of years after
the Mayans were gone.

Teotihuacan was a high point
in the history of Mesoamerica...

and its mysteries have
remained unsolved until now.

Gomez and his colleagues
seem to have uncovered

the very source of the city's existence.

That's what makes this
discovery so special.

By understanding their vision of
the cosmos and their religion,

we now have a much better understanding
of these ancient Mesoamerican people.