Original subtitles

NARRATOR: Cutting-edge technology

unearths a secret in the Peruvian desert.

- I don't know of anywhere on Earth, that looks like this.

NARRATOR: Drone footage reveals the truth about an ancient Arabian city.

- It's breathtaking.

NARRATOR: Cryptic rings of a giant's wheel staring up from the ground.

- It's kind of like a maze, which only makes it more mysterious.

NARRATOR: And headless stone gods in the mountains of the Middle East.

- This is a place not short on mysteries. It's incredible!

NARRATOR: Everywhere we look on our planet,

there's evidence of the past.

NARRATOR: In nature...

in buildings...

in relics.

NARRATOR: Each holds a mystery

that technology now allows us to see from above.

What new secrets are revealed?

Across the globe lie countless

magnificent and mysterious ancient structures...

..each one holding long-hidden secrets

that can only be uncovered by a view from above.

To the west of Peru's Andes mountains

is one of the driest regions on Earth -

a land that has remained virtually unchanged for millions of years.

Here, around 14km from the Pacific coast,

drone footage reveals a bizarre ridgeline

carved into the mountain landscape.

- What are we seeing here? - It looks like there's a hill

and what appears to be the scales of a dragon along its back,

as if one were buried there, with its treasure, perhaps.

- I've never seen anything like this. What is this place?

NARRATOR: This massive hilltop structure is known as Chankillo.

And this uncanny site has been a mystery for centuries.

- Chankillo is several hectares in size.

Chankillo contains several monumental human constructions

that are spread out over this deserted landscape.

Part of it is a huge construction known as the Fortified Temple.

It's a fortification that contains and protects a temple

that is probably devoted to the cult of the sun.

But the area of Chankillo is clearly defined by the 13 towers.

NARRATOR: These strange towers loom above Chankillo,

arranged in a perfect line from north to south.

- Why are you erecting a series of towers

along the top of a hill in the middle of a desert?

- Are the 13 towers part of an elaborate defence -

maybe observation posts or watch towers?

NARRATOR: Perhaps a clue can be found 13,000km away

in the Judean Desert of southern Israel.

WOMAN: Here, the legendary fortress of Masada

looms high above the Dead Sea.

This isolated rocky bastion

witnessed the defiant final stand

of survivors of the Jewish revolt against Roman rule

after the fall of Jerusalem in 70CE.

- When we look at Masada

what we see are some unmistakable similarities to Chankillo.

- Both sites are on high ground.

YATES-ORR: But Chankillo is not nearly as dramatically constructed.

Whereas the edges of Masada deliver a more natural fortress

with steep mountain slopes that make it virtually unassailable.

- At the Chankillo complex there are no signs of turrets or battlements.

- Architecturally,

these towers don't look like they were built for defence.

NARRATOR: If these ruins aren't the remains of an ancient fortress,

what else could they be?

- My initial interest in Chankillo

was to study the origins of warfare in the Andean pre-Hispanic world.

But I also found, in the literature of the 19th century

travellers and explorers,

a mention of the number of towers -

13 - as a clue into a possible astronomical function.

- The rising and setting of the sun, the solstices, phases of the moon

and the position of particular stars and constellations

have been used in all ancient civilizations

to determine seasons, months and years.

- Wherever we take a closer look at ancient sacred structures,

what we often discover is that in every culture,

people are preoccupied

with measuring and recording the passage of time.

NARRATOR: Ancient time-keeping structures

have been discovered all over the world.

And there may be a clue at one of the oldest of these sites

10,000km away in Crathes, Scotland.

- The Warren Field timber hall is an impressive archaeological site

associated with the earliest farmers in northern Britain.

A total of 12 pits were revealed here.

- The pit groups' relative sizes and distinctive shapes

are highly suggestive of the lunar phases.

- Archaeologists were able to prove that the pit alignment

was developed to mirror the phases of the moon,

passing from one to the next along the alignment.

- Could this be what's happening in Chankillo?

- We needed to research the possibility

that these were horizon markers.

That these were the lines of a ruler

built on the sky to keep track of the sun.

- For that to work,

you need to position something like the towers

along the arc that the sun describes on the horizon.

But you also need to determine a fixed point on the ground.

We hypothesized that this was the observing point.

Let's imagine this is the astronomer's chair,

where he or she sits and looks through the telescope

to study astronomical phenomena.

This relatively narrow corridor

is actually leading to a particular point

where you can see the 13 towers

in their most magnificent presentation.

This wall, even though right now on the surface

you cannot see all of it,

when excavated it continues...

,,up to this point forming a narrow threshold.

This turned out to be a very, very special place.

Even if you are two metres behind the threshold...

..you will not see the full 13 towers.

I like to think of it as the focus mechanism in a lens.

Only when you are in the right position,

does the picture come into focus.

Here, just as well, only when you are at the right position,

do you have an unobstructed view of the 13 towers.

NARRATOR: At one end of the line stands a tower

that marks the June solstice.

And, at the other end, another marks the December solstice.

A space between the two middle towers marks the equinox.

Every tower in between marks a date.

GHEZZI: We have estimated that you can determine any day of the year

with a precision of one or two days.

So it's really an amazing device that is highly precise,

especially in the context of a society without a writing system.

While there is a west observing point where we are right now...

..we hypothesized there must have been,

on the other side of the towers, an equal building

containing an east observing point. But we had to prove it.

- Finding this eastern observation point

is the crucial piece to proving how this amazing calendar worked.

- If Ivan's theory is correct,

the 13 towers not only tell the time of day at sunrise

but will also be able to do the exact same thing at sunset.

- That would make this the most sophisticated solar calendar

on the planet.

- But in the four square kilometres

of windswept rock outcrops and sand ramps

it was like looking for the proverbial needle in a haystack.

NARRATOR: In order to crack this centuries-old case,

researchers turn to a high-tech view from above.

- This is a thermal camera, not a normal optical camera,

so the sensor is actually reading temperature.

Chankillo is a place where most of the archaeological features

are very close to the surface.

But when they're buried, we cannot see them with normal drones.

(drone whirs)

Infrared technology takes advantage of the fact

that these materials that are buried under the surface

absorb solar radiation during the day

and emit this radiation at different temperatures at night.

So we come here with this drone at night

and we can take pictures that are actually

thermal images of what's going on

and we can see it in the form of a map.

NARRATOR: What will this cutting-edge view from above

uncover about this 2,000-year-old mystery?

- When flying the drone armed with an infrared sensor

over the area where we expected the east observing point to be...

..we were able to see this small structure.

There's absolutely nothing else

except this relatively small platform

leading us to conclude that, yes, it is an observing point.

It was really like a eureka moment for us.

It was a very exciting moment of celebration.

We kept coming at night,

for sunset, for sunrise, to recreate that sense of discovery.

Without the view from above

it would have been nearly impossible

to prove convincingly that this was an east observing point.

- This eastern observation point

proves the ancients tracked the movement of the sun

as it passed over the towers from the east as well as from the west.

Observing the towers from both ends

meant they could tell time at sunrise and at sunset.

- One of the things that amazes me about Chankillo

is that we are experiencing exactly the same astronomical phenomena,

the same alignment that people designed to watch.

And that is incredible.

I feel like I'm being transported into the past 2300 years

by seeing exactly the same magical phenomenon

that occurs here every day.

- Truly a masterwork that could only be fully appreciated from the air

and a mystery that could have only been solved with a view from above.

NARRATOR: From sun-baked rock to arid sands,

ancient structures rise in remote and unforgiving landscapes.

On the parched desert plains of north-western Saudi Arabia...

..a majestic monolith rises from a lonesome outcrop of sandstone.

This strange edifice rises a stunning 23 metres high.

- It sort of looks like a massive, grand house.

- Could the monolith actually be a sandstone dwelling?

NARRATOR: Perhaps a clue lies 12,000km away,

nestled in the Colorado Cliffs of Mesa Verde.

- Mesa Verde has over 600 Puebloan abodes

built into natural sandstone alcoves.

- Many of these homes have multiple rooms

and some structures are large enough to house at least 150 people.

- There are over 4,000 archaeological sites

weaved into the landscape,

from small villages, to longhouses.

And there's even a palace built into the cliff.

AGRAWAL: But this monolith is completely standalone.

There doesn't appear to be any immediate neighbours

like you can see with a lot of the dwellings at Mesa Verde.

HOFFMAN: It seems so strange for someone to build a big house

with no windows and one door in the middle of the desert by itself.

NARRATOR: This mysterious monolith on the Arabian plains

is known locally as Qasr al-Farid.

- From Arabic to English, this translates to the Lonely Castle.

- The exterior is fabulous

but it doesn't seem to have the same attributes

found at other Arabian castles in this region.

- It's not built on a slope and there are no artillery walls

or towers.

- There are rough, unfinished chisel marks on the lower third,

which makes me think that it was actually carved from the top down.

- Which is really odd because castles, lonely or not,

normally start life from a firm foundation

and are forged from the bottom up.

- I'm really not convinced that this is a literal castle.

NARRATOR: The Lonely Castle is indeed not what it seems.

Undisturbed for almost 2,000 years,

it's a sandstone sculpted burial tomb.

NARDI: It's a huge tomb.

Was this built for someone extremely prominent in the ancient world?

- The tomb was apparently paid for by a decorated general

who died in battle before it was finished.

But I don't think he's even buried here.

- Usually tombs like this aren't solo,

they're the centrepiece in a bigger complex

to show off the deceased's wealth and social status.

- Is there more to uncover here?

NARRATOR: To find an answer, we search with a vast view from above

and discover the lonely castle is not as lonely as we first thought.

- It appears so isolated

but it's actually the largest of over a hundred tombs.

- There's over ten square kilometres of desert

with numerous buildings hand-carved into giant boulders.

- There seem to be clusters of necropolises

disguised by the natural landscape.

NARRATOR: This is the Al-Hijr Archaeological Site,

also known as Hegra.

- What I really want to know about Hegra is this -

who is inside all of these tombs?

- All the tombs vary in size, from one small room to larger chambers.

Some are easily accessible,

but others you have to brace yourself to climb into.

- I would imagine the bigger tombs can hold numerous graves,

depending on the status and size of a family.

NARRATOR: Perhaps a closer view from above

can reveal clues as to who's inside these tombs.

- They're each decorated differently with crowsteps, eagles,

intricate figures, snakes and sphinxes.

Sphinxes? Those are those mythical hybrid creatures

that you mostly get in Ancient Egypt.

- Is it possible that pharaohs were entombed

all the way over here in Saudi Arabia?

- I don't think so.

Pharaohs were typically buried in pyramidal shrines.

- And don't rock-carved Egyptian temples

typically heavily feature

Osirian pillars and hieroglyphs?

We're not seeing those here.

- On some tombs, you can find the monstrous face of the Gorgon Medusa.

I'm pretty sure that's the calling card of the Greeks.

- Don't you think the columns look quite Romanesque?

- There's obviously a mix of influences -

from Greek to Roman and Egyptian.

- Could all of these people be buried here?

- It's not impossible but I'm more inclined to suggest

that these motifs were just borrowed by someone else.

NARRATOR: A closer look at the decorations on the tombs,

reveals even more clues.

- More than 50 facades have inscriptions or petroglyphs

etched into the rock.

- Can these writings tell us exactly who's buried here?

They might, but how are we going to translate the language?

NARRATOR: Perhaps a key to this cipher

can be found only 14km away

on mount Jabal Ikmah.

- Jabal Ikmah is considered a crossroad of civilizations.

- This mountain contains around 450 inscriptions,

writings and drawings on its rocky cliffs.

- There are messages from several kingdoms still set in stone.

- It's an unprecedented collection

of the region's most ancient languages,

which we can use as a sort of open reference library.

NARRATOR: Like Jabal Ikmah,

the monumental tombs at Hegra feature early Arabic dialects

but also Latin and Greek.

- It's such an assortment of prose,

it seems impossible to know who used this necropolis.

NARRATOR: Perhaps what is needed to solve this mystery

is not a view from above but a view from within.

NARRATOR: In 2008, archaeologists excavating the tombs

found crucial clues - human bones buried with impressive artifacts.

- The people entombed here were definitely elite.

The expensive treasures buried with them include coins,

bronze bracelets, rings, necklaces and glass beads.

- And there are also commodities like combs, cosmetic tubes

and embroidered handkerchiefs.

- Organic material and textiles found on the bones

show the bodies were carefully covered with a mixture

of fats and resins from incense-bearing trees and shrubs.

- Wasn't it the Egyptians who famously use resin

in their funerary rites? - They did.

But so did the Romans. And the Greeks.

It was a typical ancient burial practice for important people.

- That gives us the usual suspects but no actual answers.

- This is somewhat blowing me away. I mean, who on earth do these bones,

wrapped up in leather and slathered in balm, actually belong to?

- To our surprise, most of the remains uncovered at Hegra

are dated from the ancient Nabataean Kingdom from the 1st Century CE.

NARRATOR: The Nabataeans were a nomadic tribe

who brought considerable wealth and influence across the ancient world.

But the discovery of their remains here, at Hegra,

raises more questions than answers.

- How did they get here?

I mean, the Nabataeans aren't known to have originated from this area.

- Why would they be entombed that far from home?

NARRATOR: Perhaps the answer to this desert riddle

lies 450km away in Jordan,

home to the once mighty capital of the Nabataean Empire,

the ancient city of Petra.

- The remains of Petra in Jordan feature royal Nabataean tombs,

obelisks, temples, palaces and sacrificial sites.

- You've got houses, you've got streets, you've got an amphitheatre,

you've got a monastery, and even a treasury.

NARRATOR: Petra is one of the world's

most spectacular archaeological sites -

a massive, ancient city made of more than 500 ornate buildings and tombs.

- All so skilfully engineered into sandstone...

just like the tombs at Hegra.

- Does that mean it's possible Hegra isn't just a necropolis?

NARRATOR: Could the Nabataeans have built

a second, giant city in the desert?

- Was Hegra actually once a bustling metropolis?

NARRATOR: Answers to this mystery may be revealed

by another view from above

over the ancient Nabataean capital of Petra.

- These two Nabatean wonders are both carved from sandstone

with similar designs, decorations

and both are home to hundreds of tombs.

NARRATOR: Could Hegra and Petra have been sister cities?

And what histories could these two stunning sites have in common?

- We know that the Nabataeans at Petra

were really prolific wheeler dealers

and they were trading spices and silk

with China, India, Rome and Egypt.

NARRATOR: Petra was a thriving trading hub on the Incense Route,

a network extending over 2,000km

that allowed traders to transport goods

from the Near East across the Arabian Peninsula

to the Mediterranean.

- So, you've got to ask yourself, if Hegra was Petra's sister city,

was it also an important pitstop on the famed Incense Route?

- Yes. Hegra was a crossroads of commerce,

perfectly situated where the north-south Incense Route

intersected with other inland trade routes.

- Hegra was an important stop

for traders crossing the Arabian Peninsula

carrying frankincense, spices and luxury goods from Yemen and India.

- Which likely explains many of the borrowed cultural influences

found at Hegra - people from all walks of life came through here

and inspired the Nabataeans.

- But why did life at Hegra end?

- The Nabataeans were basically eventually forgotten

after the Roman emperor Trajan conquered them in 106 CE.

- The archaeological remains were never reused or restored.

NARRATION: And Hegra's legacy faded into the desert.

- There's no doubt that Hegra

is among the best-preserved archaeological areas in the region.

- And, amazingly, in over 2,000 years

it hasn't been impacted by any urban or industrial development.

- Meaning what's left here at Hegra

is probably one of the most reliable representations

of the Nabataean civilization in the entire world.

NARRATOR: An incredible testament to the past best discovered from above.

NARRATOR: From giant mysteries carved by ancient civilizations

to cryptic mountaintop formations,

the view from above reveals centuries-old secrets.

Atop the militarized zone of the Golan Heights

between Israel and Syria

lies a part of the world that is home

to the oldest traces of human history.

- This part of the world has been at the crossroads of human history

since before the first words were ever written down.

NARRATOR: Here the view from above

reveals one of the strangest sights in the entire Middle East...

..a giant spoked wheel made from piles of stone.

- This place is massive. You can't take it in from a human height.

There are no hills around, there are no mountains.

So, whoever built it, they couldn't actually see these circles.

- So, how did they construct it in such a picture-perfect radius?

And who did they do it for? What is the purpose of this place?

- In a land steeped in history, it could be just about anything.

NARRATOR: In Arabic, it is called Rujm el-Hiri,

meaning the "stone heap of the wild cat."

In Hebrew, it is named Gilgal Refaim,

a reference to a race of giants in the Bible.

For others, it is simply called the Giant's Wheel.

- Sitting in plain sight but unnoticed for centuries,

it wasn't until after the Six Day War of 1967

that the Golan was surveyed by archaeologists

and this structure was spotted by Israeli aerial reconnaissance.

NARRATOR: From above we see that this mysterious structure

consists of a large circle of rocks,

containing four smaller concentric circles,

each progressively thinner and some incomplete.

Between the circular walls are interconnecting radial walls,

creating the shape of a wheel.

- So, what is this thing?

- That's a question historians, archaeologists

and other experts have been asking for years.

No other structure like it has been found in the Near East.

- When I see the full layout from above,

it reminds me of one thing in particular and that's castles.

Actually, concentric castles if I'm going to be exact.

- This is the holy land, after all, and the crusaders brought

a whole new level of fortresses to the region.

- Is this what we're seeing?

The ruins of a once mighty Christian stronghold?

- Well, the location is certainly on-point.

For centuries, European powers clashed with Muslims

for control of holy sites considered sacred by both groups.

And present-day Israel was in the middle of it all.

NARRATOR: Could the Giant's Wheel

have been some kind of crusader fortress?

NARRATOR: Roughly 40km to the southwest lies a possible clue -

the crusader castle of Belvoir.

- Built around 1168, it is one of the earliest known

and best preserved examples of concentric castle design.

- The main feature of a concentric castle is a set of circular walls.

You have this inner wall built out of stone

with turrets positioned at intervals and then that is all surrounded

by this equally thick but lower stone wall on the outside.

The walls are at different levels

so the people on the inside can shoot things out

without hitting the people on the outside. Goes over them.

- Although Belvoir Castle is not circular, like some others,

you can still clearly see by its ruin's footprint

how it looks like one castle nested inside another.

The similarity to the Giant's Wheel is striking.

- But the walls of the Giant's Wheel were never high enough,

even in their prime, to give a strident defence

like you would see in a concentric stronghold

like the one at Belvoir Castle.

- And there's no evidence of a moat or a drawbridge.

- And the Giant's Wheel is not situated

in a particularly strategic location

or at least not one that's very obvious to any modern eye.

NARRATOR: And there's another problem with the fortress theory.

- The Giant's Wheel is very, very old.

Thought to have been built around the year 3,500 BCE.

RISKIN: That means it's older than the Egyptian pyramids.

That's way before the crusaders ever got anywhere close to this land.

NARRATOR: So if the Giant's Wheel wasn't built for defence,

what was its purpose?

- Archaeologists believe the site

could likely have been a ritual centre of some kind,

possibly one linked to a cult of the dead.

- We know other Neolithic circles

were built for worshiping ancient gods

or for the commemoration of the dearly departed,

both of whom would have been able to see those circles from above.

YATES-ORR: Is this what we have here in the Golan Heights?

A centre for a cult of the dead?

NARRATOR: Roughly 550km to the north,

another ancient structure may offer a hint.

Atop a limestone plateau

in the arid southeastern Anatolia region of Turkey

stands the world's greatest and oldest known megalith temple -

Gobekli Tepe.

BELLINGER: Gobekli Tepe is a complex

of more than 20 circular stone enclosures.

Archaeologists believe the sprawling 11,500-year-old site

was first used at the dawn of the Neolithic period,

which marked the appearance of the oldest permanent human settlements

anywhere in the world.

HOFFMAN: This is as old as history can get.

We're talking over twice as old as the Giant's Wheel.

NARRATOR: Discovered in the early 1960s,

archaeologists believe Gobekli Tepe was a sanctuary

used by widespread groups of nomadic hunter-gatherers.

RISKIN: This site is built up of a bunch of circular structures

supported by these massive stone pillars.

And here's the thing - these were crafted and arranged

by prehistoric people who had not yet developed

metal tools or even pottery.

- The similarity with the Giant's Wheel,

it's incredible, actually, because you've got these

concentric rings that are connected by these radial walls,

which are kind of like spokes, and they're at irregular intervals.

And what they do is to divide the circular areas

into unequal segments.

- But, unlike the Giant's Wheel, the pillars of Gobekli Tepe

are richly decorated with figurative anthropomorphic details

and reliefs of wild animals

providing archaeologists with rare insights

into the particular iconography of the period

and even prehistoric spiritual beliefs.

- Anthropologists point to these stone carvings

as proof of a cult of the dead,

inferring that the carved animals are there to protect the deceased.

NARRATOR: With no such carvings at the Giant's Wheel,

does the Gobekli Tepe cult of the dead offer other clues?

Are there other powerful symbols here at work?

What could the concentric circular design mean?

- Researchers suggest that the concentric circle design

might represent ripples on the surface of a lake

when an object is dropped into the water -

circular undulations that symbolise

the miraculous cycle of death and rebirth for the ancients.

NARRATOR: Throughout history, and even pre-history,

humans have built long-lasting monuments to honour their dead.

- Is it possible that the Giant's Wheel

was originally an elaborate grave?

- We know that these neolithic tombs, called dolmans,

are formed by getting this large slab

resting on these stone uprights

to form a kind of protected tomb.

Now, these are common throughout Europe, the Middle East and Asia,

but these structures are rarely constructed

in a series of concentric rock circles

like we see on the Golan Heights.

NARRATOR: Can a closer look at the centrepiece of the Giant's Wheel

reveal an important clue?

YATES-ORR: At the centre of the Giant's Wheel is this chamber.

Is it possible that it's a burial chamber?

HOFFMAN: Despite extensive excavations,

precious few relics have been found.

To date only some bronze arrowheads, a single pin and golden earrings.

- But, and most importantly,

no human remains have been found.

And, even more confounding,

some archaeologists have recently claimed that the central dolmen

was built from smaller rocks

that were assembled roughly 1,500 years

after the surrounding walls were constructed.

- Meaning even if it were a tomb,

that may not have been the site's original function,

as the dolmen tomb may be over a thousand years newer

than the site itself.

- We're not only left with questions of who the dolmen was built for,

we're not even sure it was built as a burial chamber in the first place.

NARRATOR: Could there be another explanation?

- When you've got so few artifacts recovered at the site

and you've got no human remains,

maybe the Giant's Wheel was a different type of mausoleum -

a place where the deceased weren't actually buried

but rather were laid to rest.

- We might be left with a rather grisly conclusion -

the Giant's Wheel was an excarnation facility.

- What we might have here is a sky burial.

- The bodies of the deceased would be placed

on top of stone mounds or towers, out in the open air,

so they could be picked clean by vultures.

NARRATOR: Still practiced today in remote parts of India,

China, Tibet and Mongolia,

sky burials were once popular in the ancient Middle East.

And signs of this tradition still stand in nearby Iran,

structures known as Towers of Silence.

- A Tower of Silence is a circular, raised structure

built for excarnation -

that is the exposure of human corpses to the elements

for decomposition.

RISKIN: The Yazd Tower of Silence in Iran is an excellent example.

This ancient circular tower still stands but it's not used any more.

- Could this be what we're seeing in Israel?

Is it the remains of a sky burial platform?

- Although the practice of excarnation was widely practiced

all throughout this region by many different groups,

it's impossible for experts to know if the Giant's Wheel

was intended for this purpose.

NARRATOR: Today, the truth behind the Giant's Wheel

has yet to be uncovered.

- Someone built this huge structure.

We just don't know who or why

or exactly when or how.

- The Giant's Wheel remains an absolute mystery

and it's one that can only be truly appreciated when viewed from above.

NARRATOR: On the highest peak of the Eastern Taurus mountains

in southeastern Turkey,

an ancient site holds an eerie mystery.

- What is this place?

It looks like a mountain top

crowned with a huge pyramid.

- It's like a mountain sitting on top of another mountain.

NARRATOR: This is Mount Nemrut, a 2,000-metre peak

crowned by a monumental limestone shrine,

built to honour an ancient king.

- Beneath this massive mound of rocky fragments

is rumoured to be the final resting place of King Antiochus I,

who ruled the ancient Commagene kingdom in the 1st century BCE.

- And there appeared to be giant stone carved heads...

..and some of these, they kinda look like garden gnomes.

- These stone heads represent King Antiochus I

and they're a deified anthropomorphic representation

of his Commagene kingdom

and a whole kind of other assortment of Greek and Eastern gods

with a lion and an eagle at each end.

- The fact that King Antiochus I commissioned sculptures of himself

alongside two lions, two eagles

and various Greek and Eastern gods

is compelling proof of his megalomania.

- He was a ruler who thought he was equal to the gods.

- Archaeologists have long wondered if the good king Antiochus

does indeed lie hidden underneath the massive stone tumulus.

Any substantial digging is pretty much impossible

without disrupting tons of stone.

- This is a place not short on mysteries.

I mean, how did the ancients amass this enormous quantity

of limestone fragments?

And then how do they transport it

to the top of the mountain? It's incredible.

And an even more compelling mystery is...

why are these giant stone heads here? What was their purpose?

- It certainly wouldn't be the only place in the world

where lone giant stone heads reside.

- Could there be clues lying with other, ancient cultures

who crafted really similar, massive stone heads?

NARRATOR: Perhaps a clue can be found

17,000km away on Easter Island,

home to the most famous oversized heads in the world.

- And, to be honest, the only reason anyone knows where Easter Island is.

- Here the Rapa Nui people created giant heads called moai

as monuments to honour ancestors and chiefs

whose supernatural powers were believed to protect the community.

- Between roughly 1100 and 1650 CE,

Rapa Nui carvers create some 900

of these kind of very minimalist sculptures,

nearly all of which are still in situ.

BILLSON: The giant stone sculptures

commonly weigh between 10 and 12 tons.

Their average height is roughly 13 feet,

but some are much taller,

considerably larger than those on Mount Nemrut.

- Contrary to common belief, the moai are more than just giant heads

they're actually whole-body human figures.

Their oversized heads epitomise a sculptural trait

consistent with the Polynesian belief in the sanctity of the head.

- As with the giant heads on Easter Island,

could the giant heads at Nemrut have been carved

in honour of the spiritual power of the head?

- A view from above reveals there's something very different

about the heads at Mount Nemrut - and it's standing right behind them.

- The stone heads are not solitary sculptures

but rather belong to their statutory bodies whose bases stand nearby. -

These giant stone heads that we see today

were actually set upright by archaeologists decades ago

and they were once actually connected with their stone bodies.

But, at some point, as we can see, they've been beheaded.

- So why did these huge stone statues lose their heads?

- One theory that deserves attention is perhaps the simplest.

Maybe the heads of King Antiochus and fellow gods and guardians

were just victims of wear and tear over time?

BILLSON: This region is legendary for its harsh environment.

The desolate windswept mountain top

is exposed to all manners of erosion.

- Maybe they just fell over? Gravity as they say, always wins.

- But all ten statues? And only the heads? That seems highly unlikely.

NARRATOR: Could there be another natural phenomenon

behind the beheading of these giants?

(heavy rumbling) - (panicked shrieking)

BELLINGER: This part of the world is notorious

for its unpredictable and catastrophic seismic activity.

Earthquakes have devastated parts of Turkey

since the beginning of recorded history.

NARRATOR: Much of Turkey is located on the Anatolian plate

which is squeezed by the collision of two other tectonic plates,

the Arabian and Eurasian.

- And Mount Nemrut sits right in the crosshairs

of these colliding tectonic plates.

- Could previous tremors over the past 2,000 years

be responsible for the toppling of these stone heads?

- Although this part of Turkey is prone to violent seismic activity,

the likelihood that all ten heads,

and only the heads, break off, seems very improbable.

KOUROUNIS: So, what separated these heads from their bodies?

The next theory to consider

points to the handiwork not of Mother Nature, but of humans.

- When you have the fall of the Roman Empire

and the fall of the Greek Empire before it,

you get the systematic destruction

of many of their buildings and cultural emblems.

So, the heads and limbs of countless statues

suffered significant damage as they were toppled.

- Fully intact statues are seldom found, archaeologically.

AGRAWAL: Did the statues at Mount Nemrut suffer a similar fate

through acts of vandalism?

Or perhaps looters seeking royal treasure from the burial mound?

BELLINGER: Archaeologists are confident the immense stony tumulus

has remained impregnable since it was constructed two millennia ago.

So looting probably isn't the answer.

- OK, we can't rule out centuries of roving bands of ne'er-do-wells,

but a closer look at Nemrut

leads experts to a really different conclusion.

NARRATOR: An examination of the statues

reveals that they were not carved as one piece

but were instead made of multiple pieces assembled together.

Is it possible the heads were designed for easy replacement?

- In Roman times, the removal of statue heads

was sometimes a matter of pragmatism.

Roman statue makers often created

interchangeable, archetypal body types

to be married with separate, highly individualised heads.

If a sculpture of a hero or an eminent person or ruler

lost their good name or their honour or they just simply died,

the head was easily removed and replaced by a new hero,

a better-known person or a new ruler.

- The heads at Nemrut were crafted separately from the statues

so, theoretically, they could have been replaced or even swapped out.

But weighing tons apiece

and requiring weeks, if not months, of sculpting -

never mind the arduous task

of transporting them to the top of a mountain -

all that seems like a highly unlikely scenario.

- Instead, archaeologists believe that at some point

there was a collective effort to demolish the statues

with no heed to King Antiochus I

and his desire for eternal recognition. Too bad.

AGRAWAL: Historians simply don't know.

Despite King Antiochus I's best efforts to deify himself,

maybe his own people soured on him?

That could explain why people chose

to vandalise symbols dedicated to him.

(crowd cheers)

- We've seen parallels of this in modern times;

from ISIS demolishing pagan statues in Syria

to Americans tearing down or vandalising statues

of their own problematic historic figures.

- This policy is known as damnatio memoriae,

a Latin phrase meaning "condemnation of memory."

What this does is indicate that a person

is being excluded from official accounts.

They're being cancelled in some way.

Now that someone could be considered a tyrant or a traitor

or some other enemy of the state

and they're being vilified for some reason

and basically cleansed, expunged from the collective memory.

NARRATOR: Is this what happened to the statutes on Mount Nemrut?

- If so, what caused the turn against Antiochus?

Archaeologists and historians

can't point to any historical record or particular event

that may have turned the people against the good god-king Antiochus.

- Perhaps the key to solving the mystery is the heads themselves.

AGRAWAL: Again, we look at ancient Romans for insight.

If a particular person was hated after they died

the Romans would chisel away and deface any statue of them.

- When we take a closer look at the damage on the stone heads

we're left with one conclusion - that damage was intentional.

BILLSON: There's a pattern to it, particularly their noses.

When and exactly why it was done is lost to history.

But the facial damage was not caused by strong earthquakes

or kids pulling a prank.

it was deliberate.

- King Antiochus was a small ruler

with big ambitions and an even bigger ego.

And that, as we know, can sometimes rub people the wrong way.

KOUROUNIS: Inscriptions found at the site

commanded that people celebrate his memory for eternity.

Unfortunately, his imperial cult

didn't last for long after his death in 38BCE.

- But his statues survived on top of Mount Nemrut.

OK, but they were in pieces.

No-one knows for sure why they were decapitated or who did it,

but here they lay.

BELLINGER: Inscribed on the walls are the parting words

of the self-styled King God Antiochus.

Warnings to those who would harm this work.

They go something like this,

"Whosoever, whether king or emperor,

harms the gods or this monument,

may they face all manner of catastrophe."

- It's only with a view from above, that we can fully observe

the legacy of King Antiochus' shrine to himself

and the mystery that surrounds it, lying unsolved in broken stone.

NARRATOR: From an ancient calendar carved into

a Peruvian mountain ridge...

...to a city of the dead in the Arabian desert,

to a mysterious wheel named for giants

and headless sentinels protecting a once-mighty king,

all long-standing secrets best explored from above.

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