All language subtitles for (SDH).eng

On a scale of one to ten,

Downloaded from
YTS.MX

if those anomalies are voids
or passageways,

it's an absolute ten.

[narrator] A revolution in technology

Official YIFY movies site:
YTS.MX

is opening up a golden age
of archaeological discovery.

[Jaskolski] This is it. This hole here
drops off a good 60 feet deep.

Totally fatal to fall down.

[Guillermo "Memo" De Anda] Let's do it.

[narrator] And National
Geographic has exclusive access

to document this ground-breaking journey.

[Jaskolski] Any time you do
a dive with a bunch of new technology

and you come back with all the technology,
that's a win, right?

[narrator] This team of explorers,

led by one of the world's
foremost experts on the Maya,

are embarking on
an unprecedented expedition.

[Chris Millbern]
I'm definitely seeing stuff.

I'm pretty wildly excited right now.

[narrator] On a quest
to stare deep underneath

the hallowed grounds of Chichen Itza

using lasers, drones,

and digital 3D modeling.

[Jaskolski] That's a big anomaly
that I didn't expect to be there.

[narrator] All in an effort to unearth

one of the world's most epic mysteries

beneath one of the greatest civilizations.

The Buried Truth of the Maya.

Sixty-five million years ago...

an asteroid careened toward Earth

and smashed...

into Mexico's Yucatan Peninsula.

Its apocalyptic impact...

wiped out the dinosaurs

and killed 75 percent
of all life on Earth.

Over time, thousands of sinkholes
and underground caverns formed

through the cracks in the limestone.

Filled with water,
these cenotes set the stage

for life to take hold once more.

Many millions of years later,

a highly advanced civilization formed
around these water sources.

This life-sustaining resource
fueled the rise

of the Maya,

the largest civilization in the
Western Hemisphere at the time.

One of the most central and sacred sites
in the entire Maya kingdom was called:

Chichen Itza.

Maya is a fascinating civilization.

They're in the middle of the jungle,
they were so wise,

they did astronomical science,

and they do sacrifices
or they do offerings into caves.

[narrator] Perhaps the ancient Maya
understood this region's

cataclysmic past.

Because they also thought
that to bring about water...

and life itself,

Chaac, the Maya god of rain,
required offerings

such as jewels, bloodletting,
and sometimes...

human sacrifice.

[Memo] Scholars have said that this is

the place to deposit
the hearts of victims.

[narrator] Today, we're in a rare moment
of archaeological discovery

in the world of the ancient Maya.

Recent scientific surveys suggest that
the Maya could have built

secret underground tunnels and chambers

beneath Chichen Itza.

According to Maya folklore,

the most sacred cave, possibly
full of generations worth of jewels,

gold, bones, and other lost treasures

sacrificed to the gods,

could lie beneath
one of their holiest temples,

El Castillo.

But to this day,

this underground cave remains
one of the greatest unsolved mysteries

at the heart of Chichen Itza.

Finding an entrance into this
potential crypt under El Castillo...

would be one of the biggest
discoveries of the 21st century

and could yield untold discoveries
and archaeological treasures.

-This is a massive cavern.
-Yeah, no that's huge.

-[Jaskolski] Memo!
-[Memo] Hey, what's up!

[Jaskolski] Hey, man! How's it going?

-[Millbern] Good, buddy.
-[Jaskolski] Good to see you.

[overlapping chatter]

[narrator] Uncovering it is
bringing two teams of archaeologists

and technologists together.

[Millbern] Hey, we got something
to show you.

-[Jaskolski] Yeah, yeah.
-Check this out.

[Memo] All right.

[narrator] Guillermo de Anda,
aka "Memo"...

is an INAH archaeologist,
a National Geographic Explorer,

and one of the world's foremost
experts on Maya archaeology

and their underground secrets.

I have been told for years in this area

that there is a huge cavern
beneath El Castillo.

We know that caves have
this big preservation factor.

It's going to be big news for the world,

it's going to be big news for Mayanists

if we find a way to get into the cave

beneath El Castillo.

[Jaskolski] This is from
the droning, the LiDAR,

and the camera work around El Castillo.

[Memo] This is an amazing model,
huh? The detail...

[Jaskolski] Yeah, it's
really coming together, hey?

[narrator] Joining Memo is the
pioneering technology company

Virtual Wonders.

Together, they're creating a high-tech
3D model of Chichen Itza

in the hopes of pinpointing an entrance

into the hidden well
beneath the central pyramid.

[Jaskolski] My name is Corey Jaskolski.

At Virtual Wonders,
I'm the Chief Technology Officer,

so responsible for getting all
these crazy technologies to work

and come together
and play well in the field.

Virtual Wonders goes around the world
to cultural and natural places

and tries to 3D scan them

so that we can preserve
and share these places

with the entire world.

Working in these ancient sites
that are thousands of years old

with a ground-penetrating radar

or laser scanner that scans
a million points per second,

you can only imagine
what the people of those times

would have thought of these technologies.

They would have thought we
brought down gifts from the gods

to help understand the world better

and, in a way, that's true.

Things that I get probably
most excited about,

even far more than this data,

is El Castillo not being aligned

between Cenote Sagrado and Xtoloc.

[Memo] And we know the Maya
didn't leave anything to chance.

What we believe is they are
trying to put El Castillo on--

[Jaskolski] On top of something important.

[narrator] The city planners erected
the pyramids at the proximate intersection

between four giant underground
water wells called "cenotes"...

to the north, south, east, and west.

Curiously, the Maya built this pyramid
52 and a half feet off center

leaving it mysteriously unaligned,

which is unimaginable given the
Maya's legendary mathematical

and architectural precision.

Some scientists believe that the Maya
built this pyramid off-center

to tower above a pre-existing sacred cave,

forming a link to the spirits
of the underworld.

Could this cave be filled
with undiscovered treasures

and sacrificial offerings
left for the gods?

[Jaskolski] I would have put
this, uh, El Castillo

right between Xtoloc and Sagrado,

not, you know, not offset between the two.

The fact that El Castillo
is not well aligned

with Cenote Sagrado and Xtoloc,

which as an engineer I look at
that and I say to myself,

you know, if you asked me
to build our biggest,

most important building for our culture,

I would have aligned it well
between the cenotes.

It's off by about 16 meters,

which is a pretty big margin
of error for the Maya.

[Memo] We have to
look very, very hard on this

and work very hard on this because, Corey,

I want us there.

[narrator] The Ancient Maya's
prowess in engineering,

mathematics, and astronomy

is legendary.

They invented the mathematical
concept of zero,

and they designed their buildings
with the heavens in mind.

This can be seen twice a year
during the equinox,

when on the northern staircase
of El Castillo,

the movement of shadows gives
the impression of a serpent

slithering down into the underworld.

[Jaskolski] Not everyone
would climb this, right?

It was only the priests
and the rulers, right?

[Memo] Only them.

[narrator] Towering to impressive heights,

each of the pyramid's sides
has 91 perilous steps.

Including all four sides,

the number of steps totals 364.

The final step
into the sacred temple on top

totals 365,

the same number of days in the year.

[Memo] Wow!

[Jaskolski] This is something.

You really get a sense of its power,

which is why it existed,

to get closer to the gods and
show the power of the civilization.

[Memo] We're closer to heaven.

We're on top of the big sacred
mountain of the Maya.

Holtun right in front of us,

Sacred Cenote to the north,

Xtoloc to the south,

Xkanjuyum to the east.

[Jaskolski] To go up there
with Memo and, uh,

you know, survey the land
and look at what we're doing

is incredibly important.

So, I think there's definitely
something under El Castillo.

We don't know what, and I think a lot
more studies need to be done

in order to tell us for sure.

[narrator] To dig deeper into
this mystery,

Memo and the Virtual Wonders team are
looking to a recent study for clues

to find any entrance
into the potential cave

under El Castillo.

With their new technology,

can they crack the code
and find an entry point?

[Jaskolski] Memo,
you'll remember this data,

this is, uh, from René Chávez.

[Memo] I remember this well.
This is what started it all.

[Jaskolski] They put probes all over
the ground around El Castillo,

and they measured the,

basically how well electricity flowed
through the ground.

[narrator] Modern electrical systems
generally employ metal wire

to conduct electricity,

but depending on the circumstances,

electricity can also conduct through soil.

[Jaskolski] What he found
was these, these anomalies.

What he shows is an area
of higher conductivity

they think may be a cenote
under the El Castillo.

This is sorta what started it all.
This was the...

There were a lot of sci-- There were
a lot of media that were saying,

"They found a cenote
for sure under El Castillo."

[Memo] Yes, I know, I know.
This was a big thing.

[narrator] Various materials
conduct electricity differently,

so what could be causing
these areas of higher conductivity?

And could this be connected
to an actual sub-surface world

beneath El Castillo?

[Memo] It's not confirmed data,
but it makes sense

under the perspective
of the oral tradition,

the legends, the myths around here
that have always said

"There's something under Castillo."

[Jaskolski] Right.

If we can find the cenote,
if there is a cenote or cave down there,

which I personally believe it is,

uh, we are going to find
an amazing offering.

[narrator] Because of Chichen
Itza's historic standing,

the team can't physically
excavate the grounds.

However, by analyzing these data,

the teams develop a strategy to search
for a long-lost entrance.

[Memo] The best chance is to go

-right to the center of El Castillo...
-[Jaskolski] I agree.

...and see if we can get better results

and find a way to understand
this, uh, thing better.

It needs a lot more exploration
to figure out what it really is.

[Akasha Sutherland] Today's the GPR,
Ground Penetrating Radar.

You're moving this lawn mower
back and forth

and so while we're moving, then at the end
we get this nice clear picture

of any voids or if there are
any reflective spaces

that we don't know
exactly what's below there.

[Jaskolski] So, we're actually,
we're looking about 25 feet deep

through the ground here right now.

[Sutherland] Yeah.

[narrator] With the hopes
of tracking down an entrance,

this device gives them
basically x-ray vision below the earth

without physically altering it.

-[Sutherland] Slow?
-[Jaskolski] Yeah, a little slower, yep.

There you go, there's the pace, yeah.

[Jaskolski] Akasha is our chief
communications and outreach officer.

She's the reason that a lot
of our field stuff runs smooth.

[Sutherland] I know how to use
the LiDAR systems,

I am a strobe goddess.

So this takes thousands of images

to create a perfect 3D model
of the structure.

It's all about hitting the ground just
feeling comfortable with yourself

and once you have that established,
then everything else is kind of cake.

[Jaskolski] I mean,
her spirit is just unstoppable.

She is always happy, always smiling.

It doesn't matter what's
happening. It doesn't matter

if, you know, we're injured
and going to the ER.

She's got a big smile on her face

and is trying to lift
everybody up around her.

-[Sutherland] How's it looking?
-[Jaskolski] Looking good

[Sutherland] Yeah?

[Jaskolski] There's actually
a little anomaly

at the beginning of those stairs.

[Sutherland] All right,
I'm marking it right now.

-[device beeps]
-[Jaskolski] Cool. Got the mark.

[Sutherland] Got it?

[narrator] The GPR
immediately finds something.

Hints of a mysterious
subterranean world rise up.

[Sutherland] We don't know
exactly what's below there,

but we get this nice clear
picture of voids

or reflective spaces.

[Jaskolski] All right!

And now we can go inside and catch
the, uh, catch the inside bit.

[Sutherland] Let's go in!

[Jaskolski] Cool!

Try to bang that
right up against the wall.

Just nice and slow. Nice and slow!

-[device beeps]
-Cool.

-Whoa, I'm seeing stuff. Keep going.
-[Sutherland gasps]

[narrator] This mysterious void,

found only a few feet away
from El Castillo,

might connect to the hidden chamber below.

And if it does,
could this void lead the team

to an undiscovered entrance

and possibly generations worth
of ancient treasures

sacrificed to the Maya gods?

[narrator] Chichen Itza...

was a dominant capital of the Maya world.

Recent scientific evidence
suggests the existence

of a mysterious chamber
beneath the massive ruin of El Castillo.

[Jaskolski] I'm seeing stuff. Keep going.

[Sutherland gasps]

[narrator] And using high-tech tools,

the Virtual Wonders team,
alongside Maya experts,

are trying to find an entrance into it.

[Jaskolski]
The biggest anomaly was definitely

-on the entry over there.
-[Sutherland] Okay.

[Jaskolski] We are indeed the first, uh,

to do the GPR directly under El Castillo.

That's a huge deal.

Nice and slow and steady if you can.

Yeah, we're seeing real good
about 15 feet deep or so.

Past that, it gets a little noisy,
but there's a lot we can do

to clean this up in the software too.

[Sutherland] Awesome.

[Jaskolski] Yeah, it seems like
maybe three feet down or so

there's probably a layer of rock
that might either be natural

or might be like the base
that they built on.

-[Sutherland] Like, the substructure?
-[Jaskolski] Right.

To be able to actually image what's
beneath that, that floor is amazing,

Um, you know, on a scale of one to ten

if those anomalies are voids
or passageways,

it's an absolute ten.

So we'll have to analyze the data
and see what it looks like.

[Sutherland] Check it out.

[narrator] While Corey processes
the data...

Memo brings another member
of Virtual Wonders

into the restricted areas
of El Castillo...

[Kenny Broad] When was the last
time you were in here?

[Memo] Well, it was
about a month ago, I believe.

[narrator] ...looking for any clues
about the chamber below.

[Memo] It's magical just to be here

and thinking about
how many thousands of stone

are on top of our heads, man.

So let's not think a lot about that.

[Kenny chuckles]

[Broad] My name is Kenny Broad.
I'm the mission specialist.

[narrator] Kenny Broad is
a National Geographic Explorer

and chief exploration officer
of the Virtual Wonders team.

[Jaskolski] I would describe Kenny Broad
as a, a mad scientist.

[narrator] As an expert caver,

he and Memo may be able
to add crucial insight

on how to access
the chamber below the pyramid.

[Memo] There's very few people that have
the privilege to go in here.

-[Broad] I don't wanna wait.
-[Memo] All right, let's go!

[Broad] Being involved in a new discovery,

it gives you this feeling that
you're doing something larger

than just yourself.

[narrator] While there are no portals
to the underworld on the ground floor,

they hike up to a sacred chamber

which holds some intriguing clues.

[Memo] And this is the...

[breathing heavily]

...amazing room.

-[Broad] Oh!
-[Memo] So, here we are.

[Broad] Wow!

Oh my gosh, that's incredible

[Memo] Yeah, this is where
the king used to sit.

[narrator] This is the jaguar throne.

[Broad] So the king used to sit here?

I mean, it really sticks out,

because it still has

-I assume the original paint?
-[Memo] Yes.

[narrator] From this royal throne,

kings watched countless humans sacrificed

to the rain god Chaac

at this nearby altar.

Could their remains lie
in the veiled crypt below?

[Broad] Those are the original
insets of, is that jade?

[Memo] This is jade.

[narrator] To the Maya,
jade was a royal resource,

used to communicate with the gods.

[Broad] But there's no local jade so--

[Memo] Exactly, yeah. They,
they bring it all the way from Guatemala.

It was one very important item.

Only royalty had access to it.

This context is not only a royal context

where, where the king used
to rest and sit,

it's also a funerary one.

There's a relationship
with death here, and life.

[Broad, Memo] Resurrection.

-[Broad] The cycle.
-[Memo] The jaguar is a cycle.

[narrator] The ornate Jaguar Throne
sits in front of something

even more grim and ominous.

[Memo] This is an amazing wall
for a number of reasons,

and, uh, what we see here
is embedded, uh, bones.

They are long, long human bones

that are embedded on the wall.

There's one there.

Another one here.

There.

My assumption as an bio-archaeologist,
I believe these are leg bones.

-[Broad] Looks like it would be a femur...
-[Memo] Exactly. Or tibias.

If you ask me, I would say
yeah, that might represent

bones of ancestors.

[Broad] Right.

[Memo] Or people very powerful.

[Broad] What's your sense of what
could be behind this wall?

Well, I do really believe that there is,

uh, something
intentionally deposited there.

Given the sacredness of the site,

the importance of the place
within Chichen Itza,

I believe it could be a burial back there.

[Broad] I mean, it makes logical sense.

It makes sense, yes.

Yeah, if somebody is buried here,

it was for sure a very important person,
a king.

[narrator] Could the chamber
behind this wall of bones

have once provided a gateway
to the cave below?

[Broad] I can feel the wind
coming through here.

-It's like you've found a lead.
-[Memo] Oh yeah, yeah. You feel that?

-You feel that?
-[Broad] Yeah.

[Memo] That could be indicating
a system down there.

[Broad] No, and right,
when we explore caves,

we look for that kind of breeze.

That's a, that's a sign.

[Memo] When we feel that breeze,
it's, "Let's go."

-[Broad] Yeah.
-[Memo] Yeah, so...

[Broad] Some more evidence
that there's something beneath.

[Memo] And I think this means that

the cenote that we're looking for
might be down there.

Or maybe an entrance.

-[Memo] And you can see some, some voids.
-[Broad] Right. Right.

[narrator] Because they can't physically
alter anything inside El Castillo,

Kenny and Memo carry on

looking for other ways in, to no avail.

But back at the Virtual Wonder's
headquarters,

Corey and Akasha have processed
their GPR findings

and discover something promising.

So we did this north face first
and, uh, went along this way,

right along the fence line, about, uh,
about a half a meter from the fence line

and then this way and this way.

But what we're seeing here,

um, these areas of black,
white, black like this

are very strong radar returns.

I don't think they indicate a void to me,

but I think they indicate rock.

There's nothing that interesting
on the north side to me.

We then started over here

and dragged the south side of the GPR
right on the corner here.

Again, there seems like
there's a rock base,

but what's really interesting
to me is this return.

So this is in the, uh, south east corner
of El Castillo,

This is between three
and four meters deep over here.

-Oh, wow, that's deep enough.
-[Jaskolski] And there is, uh,

there is what looks like
a really strong return.

[Memo] And it looks like
a very irregular cavity, right?

It looks, uh, I mean,
from a single GPR radar-gram like that,

yeah, I would say that looks
like a cavity, yeah.

So like a natural cavity, I mean?

[Jaskolski] It's hard to say. It's hard to
say if it's natural or man-made.

All you can really say is
it's a really strong return

that looks like a void.

How far actually it's
from, from the corner?

It's almost exactly on the corner.

Okay, that's very, very interesting.

-[Jaskolski] Yeah.
-Wow.

[Jaskolski] What I now want to show you,
Cash and I took the GPR

in this, uh, excavated archaeology part

underneath here, this doorway
and we dragged it back,

and then the hallway turns
and goes into El Castillo

towards that rock fall.

Towards the center of El Castillo?

[Jaskolski] Right. This right here,

um, is the brightest
radar reflection I've seen

anywhere in Chichen Itza.

-I've been dragging this radar around.
-[Memo] It looks amazing.

[Jaskolski] This is to me
a pretty clear void,

um, at, look at that,
three to four meters deep.

Corey, I think this is amazing,

but what I think what amazes me more is

that both anomalies are the same depth.

-Yup.
-So it might be a tunnel,

and that's very promising.

[narrator] Could this potential
tunnel be the gateway

to the proposed cenote below?

If so, where is its entrance?

[Jaskolski] The thing with GPR
that I always think about is,

if you see something and you don't see
anything like that anywhere else,

then you're like, okay, one weird anomaly,

but the whole thing is with GPR
when you start building up a story,

when you start saying, whoa,
we're seeing weird stuff

at three and a half to four meters here...

Might have comparison.

[Jaskolski] You may be, you know, I think
it builds more meaning to me.

That's a, that's a big anomaly
that I didn't expect to be there.

None of the rest
of the area looks like that.

The other side that goes up
the substructure

doesn't have any returns
that look like this.

This is a, this is a big neon sign

-saying there's something interesting.
-[Memo] Yes!

That might be it.

[narrator] This possible tunnel
may lead in the direction

of another Chichen Itza landmark:

El Osario.

El Osario is also known
as the "Tomb of the High Priest."

Another temple on the grounds
of Chichen Itza.

Archaeologists have traditionally thought
that El Osario was built

in 980 AD

and modeled after
its bigger sister: El Castillo.

But there's an even more
stunning parallel.

El Osario kind of replicates
what we see in El Castillo.

[Jaskolski] Yeah, it
looks very much similar, yeah.

[Memo] It's a radial pyramid,
four, uh, axis stairways,

snake, snake heads at the end,

so the similarities are amazing

why not thinking there is
a cavern also in El Castillo.

Guess what, El Osario was built

right on top of a natural cavern.

We think that this cavern might
have tunnels or passageways

to get into this other tunnel.

That makes sense

because they are very close,

so it sounds like the logical
place to find a passageway

to El Castillo.

[narrator] The question is:
do these underground passageways

connect to the chamber
beneath El Castillo?

They clearly built the Osario
to be over that important cave.

[narrator] Because of the danger,
climbing El Osario

is restricted to the general public.

[Jaskolski] Just a set of Mayan
stairs, and they're super-steep.

They're probably, like, a 45-degree angle,

like the stairs outside of El Castillo.

[Millbern] All right!
So, we'll connect this up?

[indistinct chatter]

-[Memo] We're looking for tunnels here.
-[Jaskolski] Yes.

I want you guys to look
for possible areas or gaps

and see if there's a passageway behind.

[Jaskolski] Totally. Yep.

[narrator] To find any tunnels,

the team must use their high-tech tools

in a difficult to reach spot.

[Memo] Very few people have been here,

and, uh, nobody has been here
with this technology.

-Has used technology, right?
-Yeah.

I guess they had, uh,

1800s technology last time they...

It still counts, it still counts.

My name is Chris Millbern,

and I'm the director of field operations.

Anything that has to do with tech
or gear is under my purview

or at the very least is me
messing around and running around

to make sure that it works.

-Robot, cable, tablet.
-Yeah.

-Only three giant things, it will be fine.
-[Jaskolski] Yeah.

I'm definitely the one sweating the most

if nobody's noticed.

Let's go! Let's do it!

-[Jaskolski] Right!
-[Memo] Okay.

[narrator] To get underneath El Osario,

they must risk life and limb.

[Memo speaking Spanish]

[Jaskolski] Memo's about to come down.
Are you ready?

That hole is about
a 60 foot drop straight down.

Going down into this little tiny cave.

[Jaskolski] Geez!

[Millbern] Corey's on the way down!

[Jaskolski] Right, coming down.

Not a lotta room, eh?

[Memo] Not a lot of room, man.

-[Jaskolski] What's the drop?
-[Memo] Sixty feet.

[Jaskolski] Sixty feet. But this is it.

We're... we're crammed in here.

[Memo] How dangerous this place is?

-[Jaskolski] Yeah, man.
-Uh, any rock...

-[Jaskolski] Yeah, you're dead.
-You're dead.

Woo!

[Jaskolski] It's this tiny,
tiny little room.

I mean, you feel like you're in the womb.

You're just crushed
in there with Guillermo.

This must have been
such an important place for the Maya

to build this massive monument
on top of it.

[narrator] To find
any undiscovered passageways

and where they might lead,

the team breaks out
one of its most versatile devices.

[Millbern] All right, Corey,
borescope on its way!

[narrator] The borescope
has a small camera

that can snake around nooks and crannies.

[Jaskolski] Okay.

So I'm going to feed out
the borescope cable.

-[Memo] Okay.
-[Jaskolski] And Guillermo,

so we'll have to straighten this out
so the borescope can articulate

so be careful.

Uh... all right, Memo, start going.

[Memo] Okay.

[Jaskolski] Go a little bit more in.

Yeah, we got something interesting.
Here, look at this. What is this?

[Memo] I think this is the
original entrance to this cave.

-[Jaskolski] Oh, right there. Right.
-Yes.

-[Jaskolski] Yeah. Oh my God!
-And, uh...

[narrator] But there's something
even more intriguing

about this underground entrance.

The passageway has been
mysteriously blocked

by something man-made.

[Jaskolski] Do you think they're
cave-in, or do you think

they were, uh, blocked by the Maya?

-[Memo] No, no, I think it was the Maya.
-Right.

-[Memo] The ancient Maya sealed it.
-Yeah, yeah.

-Okay.
-[Memo] It was, like, completely blocked.

[narrator] Memo believes
the ancient Maya did this

because of where the passage points.

[Jaskolski] I feel like the
blocked passage

is in the direction of El Castillo.

-Wow.
-[Memo] Yeah.

[narrator] But why would
the Maya have blocked off

an underground passageway
between El Osario

and the chamber below El Castillo?

The team carries on its investigation

and stumbles upon a relevant clue.

[Jaskolski] I'm seeing something
on the walls.

See the white?

Stop there for a second.

What's that?

[Memo] Right there we see
a piece of pottery.

-[Jaskolski] Oh, that's pottery?
-Yeah, oh yeah.

[Jaskolski] Wow, wow,
hold on there for a second

-[Memo] You see all the ceramic there?
-Where?

[Jaskolski] Is that... Oh yeah!

[narrator] The Maya
ritually broke ceramic pottery

as sacrificial offerings

alongside the people they buried

in order to free their spirit.

But the place the team has
found these ceramic shards

is even more mystifying.

[Jaskolski] The ceramic is on
a little shelf up there, right?

-Is that what you're looking at?
-[Memo] No, it's not a shelf.

It's on the ceiling--

-[Jaskolski] The ceramic's on the ceiling?
-[Yeah.

[Jaskolski] You find pottery all over
the floor of the caves all the time,

but shards of pottery, you know,
hanging down like... [chuckles]

...you know, like they could fall on you
like knives from the ceiling,

and, you know, that's, that's weird.

And that's the ceiling we're pointed
towards, right, you said?

-[Memo] Yes, exactly.
-[Jaskolski] That's crazy.

[narrator] What would have prompted the
Maya to affix broken pottery

to the ceiling of this
sacred underground chamber?

[Jaskolski] Is it ritually
sacrificed pottery?

[Memo] Yeah, it is ritually sacrificed.

They, uh, used fire
as part of the, of the ritual.

-It's charcoal, mud, and ceramics.
-[Jaskolski] Wow!

[Memo] And then they mix it all together.

[Jaskolski] You think they filled this in?

-[Memo] Yeah.
-So that's the floor, really?

We're looking at maybe the floor
of what they filled in?

But it's our ceiling.

Wow!

They mixed pottery, charcoal, and dirt

and filled that in from the outside
to close off a passageway

so that the Osario shaft was the only
passage into this sacred cave.

You know, that's, that's weird.

[narrator] But why did the Maya
intentionally block

this underground tunnel?

Before they can investigate any further...

[thunder rumbling]

[Millbern] Ooh boy,
that's gonna be a big one.

Oh [bleep]!

Lightning is probably my least favorite.

[lightning cracks]

[narrator] An unexpected storm
threatens not just the investigation,

but the lives of the men below.

[Millbern] A storm of that size
is not something I like to be around,

next to a metal structure, with
my friends in a wet hole right down below.

[Jaskolski] We can't tell
it's raining at all,

but we hear Chris
from the top yelling down,

"Guys, you better hurry up!

The lightning's coming in."
And we're like, "Oh no!"

Let's go!

[lightning cracks]

[narrator] At Chichen Itza's
pyramid, El Osario...

archaeologist Guillermo de Anda

and cutting-edge technologists
Virtual Wonders

are trying to unearth an access point

to the tunnel that could connect
to the chamber below El Castillo.

-[lightning cracks]
-[Millbern] Ooh boy!

[Jaskolski] Let's go!

[narrator] But their search comes to
a grinding halt when lightning strikes.

[Millbern] So lightning's coming
in and so is the rain,

so we're trying to get
these guys out of the hole

as soon as possible.

This is a little scary.

[narrator] Trapped in this tomb
60 feet below,

they must evacuate before it's too late.

[Jaskolski] All right. Gracias.

-[Millbern] There you go! Nice.
-[Jaskolski] Gracias.

People have died being hit by lightning.

We've got this big metal frame around it
that's being used to lower people.

Whoo!

That was... that was crazy.

The lightning's just
ripping down all around.

Let's get outta here
before we're hit by lightning!

[man] Yes.

[Jaskolski] Yeah, yeah.
Chaac is, uh, Chaac is with us.

[narrator] Safely out of harm's way,

the whole team reviews what
they found beneath El Osario

to try and work out
why the Maya blocked off

this underground passageway.

[Jaskolski] Basically, we put the
borescope in everywhere it would fit.

[narrator] To help resolve this mystery,

Maya archaeologist Dr. Jim Brady
joins the team.

[Dr. James Brady] That's really terrific!

-[Jaskolski] The pottery's right here.
-[Millbern] Oh, is it that structure?

[Jaskolski] There's all the shards there.

[narrator] Dr. Brady is one
of the few archaeologists

to have really explored
the mysteries of El Osario.

His expertise could yield crucial insight

into this enigmatic blocked passageway.

[Jaskolski] Which is crazy, right?

I mean, having the pottery shards
on the ceiling was a surprise to me.

I didn't know that was down there.

-[Memo] There.
-[Jaskolski] And here's, here's charcoal,

and is that, that's charcoal,
and that is charcoal, too?

[Dr. Brady] Yes.
Those are bits of charcoal.

[Jaskolski] Okay.

[Dr. Brady] We sampled that charcoal

and have gotten a radiocarbon dates back

that come out about, oh, 725, 728 AD.

[Jaskolski] 725? Wow.

[narrator] Traditionally,
most scholars believe

El Osario was built in 980 AD.

But recent research is turning
this notion on its head.

[Dr. Brady] The Osario was built
much earlier than people think.

This is about two and a half
centuries earlier than--

-[Jaskolski] Really? Wow.
-[Dr. Brady] Yeah.

[Jaskolski] Yeah, yeah, yeah.

[Millbern] How much earlier
does that place it

in comparison to other buildings?

[Jaskolski] Like, what's El
Castillo do you think?

The Castillo would be later

and so this is gonna change everything--

Yeah, yeah, yeah, yeah.

[Dr. Brady] This is gonna change
everything because rather than

the Osario being a model of the Castillo

it might be the other way around.

[Jaskolski] Yeah. Totally. Wow.

[narrator] The carbon dating
of the charcoal is changing history

and proves El Osario
was likely built before...

El Castillo.

And for the team, the ritual use of
charcoal beneath El Osario

also provides a significant
piece of the puzzle.

[Memo] The pot shards and the charcoal,

you know, that might be indicating

some kind of a ritual.

[Broad] Is this sort of the same
idea that how they

packed everything off,
closed something off?

-[Memo] Like termination ritual, you mean?
-[Broad] Exactly.

What do you think, Dr. Brady?

It looks like it was terminated.

[narrator] A termination ritual is the act
of killing a building's spiritual force.

This exorcism typically happened
when the Maya abandoned their temples.

The termination ritual not only
closed off a building to the living,

it also stopped the temple
from being visited by the dead.

-[Sutherland] That's crazy!
- [Jaskolski] Right?

[narrator] El Osario may have
once had an entranceway

to this now blocked underground tunnel,

leading to the subterranean chamber
beneath El Castillo,

and even been part
of a sprawling subterranean world.

But because this possible
passage is now blocked,

the team must regroup.

[Memo] That, that's very interesting,

you know, we've been
desperately trying to get,

to find an entrance
to this cavern or cenote

if there is one right under El Castillo.

[narrator] Memo, who knows
the Chichen Itza underground

better than anyone on Earth,

knows of one possible opening
to the Maya underworld

that could provide an
underground gateway to El Castillo.

The only way to access it
is by using advanced technology

and facing extreme dangers.

[Memo] Watch out for snakes, please.

Yeah, the cenote is right there.

[narrator] The cenotes,
ceremonial sacred sites of the Maya,

could provide concealed entranceways

to a sprawling underground network
of long-lost passages.

But flooded with water,

they're notoriously difficult to explore,
even deadly.

[Memo] It's going to become a little bit
more slippery so careful with that.

We're gonna use a rope just to
help ourselves going down there.

[narrator] Despite this, Memo and
the Virtual Wonders team are trekking

to one of the four cenotes that surround
the central pyramid of El Castillo.

The treacherous and seldom-explored
underground cavern called...

Holtun.

[Memo] This is the
amazing thing about technology

that we can see things that the eye can't.

I'm so glad that today
we have this little robot

because, uh, there is a huge tunnel

that turns a little bit to the north
which El Castillo is,

so that might be a very good chance

to maybe connect to the cenote under it.

Every time I go down there,
I find something new.

Let's go diving.

[narrator] For the team, searching these
under-explored chambers

might be their best chance at
making a groundbreaking discovery

that could unlock one of
the ancient Maya's greatest secrets.

And if so, what riches could they find?

[narrator] In their quest to reveal
a secret underground passageway

and resolve the mystery
at the heart of Chichen Itza,

Virtual Wonders and Maya
archaeologist Guillermo de Anda

are making their way to one of
the four major cenotes

that surround Chichen Itza's main pyramid.

Deploying the most advanced
exploration tools available,

they plan to investigate
the westernmost cenote...

called Holtun.

[Memo] This is the entrance.

We can go to the south side wall.

[narrator] Searching for
an underground passageway

that could lead to undiscovered treasures
beneath El Castillo.

[Memo] Cenotes have this mystery.

There is passageways that goes
who knows where.

[indistinct chatter]

[Memo] Okay.

On rope!

[speaking Spanish]

[narrator] It's a potentially
fatal 72-foot drop,

perilous not just for the divers,
but also for the pricey gear.

-[Jaskolski] You good, Chris?
-[Millbern] Yeah.

-[Jaskolski] All right.
-[Millbern] Okay.

[narrator] Corey and Memo will scuba dive
to look for any concealed passageways.

[Millbern] Okay, we're in business.

[narrator] While field specialist
Chris Millbern pilots the ROV

from a raft inside the cenote.

This small robot submarine
fits places that humans

with their bulky scuba gear
are just too big to go.

[man] You're going down with a bag?

[Millbern] Si.

It is exactly as insane
as you would expect.

This is not a carved-out cave
that's really comfortable.

It's not a place that
a lot of people have been.

Okay!

It's some place that you have to really
know your stuff to get down into

and you have to take some risks
to make sure that your able to see it.

-[Jaskolski] Is that you?
-[Millbern] Yep, that's me.

[Jaskolski] All right, go.

Cool. Props are turning.

There you go.

-You have video?
-[Millbern] Yep.

[Jaskolski] All right!

Are you on the slowest mode possible?

[Millbern] I'm on
the slowest mode possible.

Stabilization's off,
'cause I want it to be off.

[Jaskolski] Okay.

-[Millbern] Have a good dive now.
-[Jaskolski] Yeah. Thanks, buddy!

We'll see you soon.

[rebreather hissing]

[Millbern] Go find something.

[Jaskolski] Generally, I'm against using
technology like ROVs in cenotes,

and the reason is 'cause
they have little propellers that spin

and that kicks up sediment
and silt in a lot of places,

and that sediment or silt
could contain little bones

or bits of Mayan incense,
charcoal, offerings like that.

[Millbern] I apologize for being silent.

I'm just, I'm so intently focused.

[Jaskolski] But being able
to have a talented ROV pilot

maneuver it through to see
where that passage goes,

that's critical because this place
has become incredibly sacred to me.

[narrator] In this underground lair
of the Maya gods,

the team finds
extensive evidence that Holtun

was a primary repository
for human sacrifice.

[Millbern] Oh, oh, oh.

Come on. Come on, baby!

Keep moving.

My mom said video games weren't a career.

I'm definitely seeing stuff.

Wow! This is beautiful.

We found a new cave. I am...

I am pretty wildly excited right now.

I think this keeps continuing.

[narrator] At the iconic Chichen Itza,

Virtual Wonders and Memo de Anda

have found an undiscovered,
underwater passageway...

[Millbern] I'm definitely seeing stuff.

[narrator]...that could lead
to a hidden chamber below El Castillo.

[Millbern] Wow! This is beautiful.

We found a new cave. I am...

I am pretty wildly excited right now.

This is definitely its own cave
passage worthy of exploration.

There's the entrance.

I'm very afraid of getting stuck,

but, you know,
that's how cave exploration goes.

[Jaskolski] Back in Mayan times,
that passage would have been dry,

so it would have been pretty
easy to go through on your belly

and crawl through the, the cave
and to go make offerings.

[Millbern] Okay, let's turn.

We're definitely in a,
in a large passage that, uh...

could have artifacts.

I'm checking all the shelves
that I can see

to see if there's anything
that looks man-made.

This is spectacular!

What I'm trying to do is
fight buoyancy essentially

and go a little bit farther.

I'm trying to be very careful

so that if there is anything in here
that I don't disturb it.

The difference between rock and artifact

is, is gonna be something that
we might have to look at later.

So I'm checking all of the
shelves that I can see

to see if there's anything man-made.

I actually see fish way deep
there in the cave which is amazing.

Uh, I'm really hoping
not to disturb anything,

so I have to be really careful,
but this is spectacular.

I, I honestly can't believe it.

I had no idea that
this was gonna be on the other side.

[narrator] The question is:
where does it lead?

Could it lead all the way to a crypt
beneath El Castillo?

[Millbern] It definitely goes.

[Jaskolski] In cave terminology,
we know that that passage "goes,"

meaning that it continues on
past what we can see.

How big would you,
did you think the passage was?

[Millbern] Uh, it could be 10
to even 30 feet up.

I mean, it was, it was tall.

It's really hard, it's hard
to get scale on this video

so before I, you know,
make a grand claim...

Uh, but it, it was big enough
to fit a person definitely,

and it looked like it went up pretty tall.

[Jaskolski] Wow!

We'll, we'll have to
review the video though

'cause, again, I can't get scale
out of this video.

[Jaskolski] That's awesome!

These passageways never go straight.

-[Jaskolski] Right.
-I mean, very...

[Jaskolski] This one definitely doesn't.

[Millbern] This one didn't go straight.
This one went up, left, right and down...

It could have gone in any direction.

-Absolutely.
-[Memo] Okay.

There was a lot more to it
than what we saw.

[Memo] We found a passageway.

[Jaskolski] Really successful dive.

Gracias. All right.

Any time you do a dive
with a bunch of new technology

and you come back with all the technology

and everything looks like it worked,

-it's a win right?
-[Memo laughing] Oh, yeah.

We gotta check it out on video, man.
I'm excited.

[Memo laughs] Yeah. I feel amazed

and with a lot of hope that

this can take us towards Chichen,
but Chris said it's...

-[Jaskolski] It bends.
-[Millbern] Multiple directions.

I think we had options so who knows.

It certainly is really lucky
that we had this tool with us

because there was no other way
we were seeing it today.

[narrator] Back at tech headquarters,

the team scrubs through
the ROV's footage together,

hoping to gain more insight
into this newly discovered passageway

deep inside Holtun.

[Millbern] All right, so wait
until this just goes over.

I want to show you something really cool.

So this was the constriction
that was hardest for me to get through.

[Memo] Yeah, that, that was a hard one.

No one's ever been back there,
right, Memo?

This is unexplored caves?

[Memo] No, no,
this is completely unexplored.

[Millbern] So, obviously,
it extends up this way,

and there's actually a little bit
of passages that come back

around on the back.

And then, when it drops down here...

you'll see openings all across the bottom.

I mean, it's, it's huge
compared to the crevice

-that it actually started at, you know.
-[Memo] Yes. Yes.

[Jaskolski] Right, right, yeah.

[Millbern] Look down here.

You've got a passage that comes here,
and it also goes in this direction.

[Jaskolski] Wow!

[narrator] Though they can't tell
if the passageway ultimately extends

to the potential cenote below El Castillo,

they do collect important evidence.

[Millbern] So zoom it back
just a little bit.

[Jaskolski] Zooming it back.

[Millbern] Now, here's
where I want you to check out.

[Memo] Oh, that looks like bones.

[narrator] These bones could be
the remains of offerings

to the gods.

But that's not all the team discovers.

[Jaskolski] Oh [bleep]!
Hey! Hey, hey, hey, Memo!

What is that? What is that green
bit right there?

-[Memo] Oh yeah?
-[Sutherland] Oh my god.

[Memo] Looks like a jade bead.

[Jaskolski] That was jade.

[narrator] Jade.

[Memo] Wow! [laughs]

-[Jaskolski] Yeah, totally.
-[overlapping chatter]

[narrator] In the ancient world
of the Maya,

jade was a royal resource
and a precious commodity,

used to communicate with the gods.

[Jaskolski] That's an offering, yeah.

[Millbern] Good eye, Corey!

[Memo] Yes!

[narrator] Only the elite could
make a sacrificial offering of jade.

Inside this cenote that had
mysteriously run catastrophically low

through a prolonged drought,

the rulers may have believed
that the end of the world was near.

I would suspect
when there's the worst droughts,

there are probably the most sacrifices.

[narrator] Finding jade here
in this newly discovered passage

could be a momentous breakthrough.

In a desperate plea to the gods,

the Maya elite could have used this place

to offer their greatest treasures,

all for the sake of rain.

-There's another one.
-Yeah.

This one. Look, this, this.

Wow!

[narrator] These offerings may have been
a last-ditch appeal to the gods

to save the city of Chichen Itza

from apocalyptic doom.

Gradually, by the 11th century AD,

this Maya capital collapsed,

largely due to an epic drought
that lasted over 15 years

causing the nearby cenotes
that sustained the city

to run dry.

The effects of this drought
gradually undermined the city

of Chichen Itza,

and it was eventually abandoned.

But this newly discovered passageway,

riddled with evidence of sacrifice
could someday lead

to even more offerings and treasures

and into the mysterious cave
below El Castillo.