Original subtitles

- Tonight, Chinggis Khan,

a legendary ancient ruler

who amassed unimaginable wealth.

- His riches would be worth in the neighborhood

of $120 trillion today.

- The influence of Chinggis Khan's Mongol empire

is still felt across Asia and beyond,

but the fate of his treasure remains a mystery.

- He absolutely wanted to keep his enemies guessing,

so he probably engaged in substantial amounts of deception

regarding his fortune.

- Great leaders like Khan

were known to be buried with their treasure,

but 800 years later,

neither his tomb nor his supposed hoard have been found.

- Was he buried with his treasure?

Is it scattered across Asia,

or could it be both?

- There's also a curse.

Anybody who disturbs his tomb

will actually cause the end of the world.

- Now we'll explore the top theories around

exactly where Chinggis Khan's buried treasure might be.

[dramatic music]

The Khentii Mountains, a rugged and remote region

in the most sparsely populated

nation on the planet, Mongolia.

But turn the clock back 800 years,

and it's the heart of an empire

that covers one fifth of all land on Earth,

and it's ruled by one man: Chinggis Khan.

- Historians have often struggled

to put the sheer size of Chinggis' empire

into some kind of comprehensible scale.

At its height under his rule,

it was well over 9 million square miles.

It stretched from the Caspian Sea to the Pacific Ocean.

He conquered civilization after civilization,

civilizations that have stood in many cases

for thousands of years on their own.

And now this group of pastoral nomads

are coming out of essentially no man's land

in the central steppes of Mongolia,

and winning nothing but victory after victory.

- Although a lot of times he's referred to as Genghis Khan,

we believe it's probably more accurate

to refer to him as Chinggis Khan.

But for a lot of people, especially in the West,

when you hear the name Chinggis Khan,

you think about brutality;

you think about this kind of cruel, almost barbaric ruler,

but that's really one small part of the story.

He rules, actually, with a ton of tolerance.

In a lot of ways, he's a lot more progressive

than his European contemporaries.

He understands that allowing the people that he's ruling

to continue their customs,

their religious practices,

is probably what's best for his empire.

In a lot of ways, his rule sets the stage

for the modern world.

- [Laurence] Chinggis Khan builds his empire

from practically nothing.

- The man we think of as Chinggis Khan

was born Temujin in the late 12th century,

and his father was fairly prominent within their tribe.

However, when Temujin is about 10 years old,

his father is murdered by a rival tribe

and when that happens,

all of the standing of his family

essentially declines within the tribe.

- To be fatherless in one of the Mongol tribes

is really a huge liability.

His entire family is cast out.

They're essentially homeless,

wandering the steppes,

hunting for their own food, rodents,

or whatever other animal they could find.

- At one point, there's a dispute within the family

over the distribution of food.

Temujin actually murders his half-brother

to end the dispute,

and that tells us something about his ruthlessness,

even as a young boy.

- So as Temujin grows into his adulthood,

he's able to game some followers.

He establishes this meritocracy.

So basically, if you are the strongest soldier,

if you're the best fighter, the best provider,

then you're gonna have a place in Temujin's tribe

and this really makes people

wanna join him and follow him.

- He starts to develop a reputation

for being both ruthless and crafty.

And it seems in hindsight

that Temujin was probably plotting his revenge

against the tribe that murdered his father, all along.

And here's where we see the ruthlessness

of what Temujin brings to the fight,

because he does take an awful revenge

for the death of his father.

He orders the murder

of every member of the tribe taller than a cart axle.

In other words, only small children were spared;

everybody else was killed.

- This area of the world

was characterized by groups of nomadic tribes.

There is no sense of social cohesion

like we would think of today,

living in communities together.

So because they are tribal,

there tends to be a lot of conflict

and it is that sort of situation

that almost requires someone who could step in and unify,

and that's what Temujin does.

- [Laurence] An assembly of Mongol tribesmen

proclaims Temujin their new leader

and gives him a new name, Chinggis Khan,

which means universal ruler.

He decides to expand the territories he rules.

- Chinggis builds an empire within a generation.

When you think about, this is 25 years,

how can you even draw parallel with the Roman Empire,

which is built over 400 years?

- If you resist Chinggis Khan,

it's probably not gonna end very well for you.

A lot of times there are very few people

left in a village to survive.

Often he will only allow a few people to survive

to go and tell the other villages,

the other tribes, about his cruelty

and then hopefully surrender in advance.

- The Mongols understand intrinsically

that it's inherently better

to actually convince the enemy

to surrender and collaborate,

than it is to have to slaughter them

or wear them down through an attrition approach to war.

So on the one hand,

he needs to be a fairly generous conqueror.

When he conquers you,

he offers to let you join his society

under very specific rules.

- In addition to the territorial expansion

that goes on as a result of his conquest,

he's also acquiring treasure

and treasure not just in the sense

that we might think of coins and jewels,

he's also amassing a treasure of people;

of livestock, of land.

- [Laurence] At the height of his empire,

Chinggis Khan amassed a fortune

estimated to be worth over

$120 trillion in today's money.

- When it comes to the spoils of war,

whether it was forcibly taken from a city

or given voluntarily through tribute,

the possibilities are quite literally endless.

Any kind of treasure made of anything from jade,

to porcelain, to ivory, to gold, to silver.

And so it's fair to think that all of these treasures

ranging from the far east to the edge of Europe,

may have made their way back

to the heart of their empire.

- Chinggis Khan establishes his own new currency system,

which is based on silver coins.

We also have some evidence that him and his successors

were some of the first to use paper money,

which is really interesting.

So we have to imagine that there was a lot of gold

and silver and just precious metals

floating around the empire as well.

- [Laurence] But all of Chinggis Khan's riches

can't save him from a mysterious death.

- We're not sure exactly how Chinggis Khan died,

but we do know when and where he died,

which is August 18th, 1227,

somewhere in what's today Northwestern China.

There are a lot of stories about how he died.

He was almost 70 years old at the time,

so that might have been one of the main causes.

But some stories say that he took an arrow

and he fell off his horse and suffered an injury.

There are others who say he might have died

of some disease like the bubonic plague.

There's even a story that a conquered princess

might have injured his genitalia, leading to his death;

but a lot of these sound kind of legendary

befitting a Chinggis Khan,

but will never exactly know what happened.

- The Mongols have some very interesting beliefs

about death and burial.

In particular, they believe that you really can

take it with you.

You require wealth and riches in the afterlife,

and so it is entirely plausible

that Chinggis Khan was buried

with a substantial amount of treasure.

- So most experts believe

that if you can find the burial site of Chinggis Khan,

you are going to find a great cache of treasure.

- Chinggis Khan made sure

that it would be incredibly difficult to find his tomb.

So even to this day,

we really don't know exactly

where he was buried.

He wanted it to be kept a secret.

There's a lot of legends and stories

around how this happened.

- One of which suggests that almost no one

was trusted with the actual burial location.

The troops that were detailed to create the tomb

and placed Chinggis Khan within it

were ordered to kill anyone

they met on the route to the tomb,

and were then themselves killed in turn

by a separate unit.

That separate unit was killed by a third unit,

thus continually breaking

the chain of information and evidence

as to where the tomb might be located.

- [Laurence] One of the oldest clues

pointing to a potential location of the tomb

comes from a young explorer employed by the Mongol Empire

about 50 years after Chinggis Khan's death, Marco Polo.

- Marco Polo served as an emissary

at the court of Kublai Khan, Chinggis Khan's grandson.

He reports that what he's hearing at the court

of Kublai Khan is that

the great Chinggis Khan is buried

in the Khentii Mountain region in a specific mountain,

which he does not name.

The challenge is that we're talking about

an area that is thousands of square miles.

- [Laurence] After the fall of the Mongol Empire in 1368,

the ruling powers of Mongolia

change hands several times.

Then in the 1920s, the northern region

known as Outer Mongolia,

joins the newly formed Soviet Union.

After World War II,

the southern region known as Inner Mongolia

becomes part of China, where it remains today.

- For the next few centuries,

whoever is in charge of this mountain range

is gonna make it really difficult to go in and explore.

Even once Mongolia becomes

a puppet state of the Soviet Union in the 1920s,

the Soviets also wanna keep this area off limits.

- There is the added dramatic element here

that there's a curse associated with his burial.

Anyone who opens the grave of the great Chinggis Khan

doesn't just doom their own life,

they bring about the end of the world.

- It's not really until the Iron Curtain falls

that we get to have some exploration

of this region of the Khentii Mountains.

So, starting in 1989,

people come and start exploring the region

looking for his tomb.

- [Laurence] During this time,

a wealthy Chicago commodities trader named Maury Kravitz

grows obsessed with finding Chinggis Khan's tomb.

- He identifies multiple locations

in the Khentii mountains

that he believes might hold the remains of the great Khan.

In the summer of 2000, he's ready to begin.

Almost from the beginning,

the Kravitz expedition is all but doomed.

His horses become exhausted

when they're only halfway to the elevation

of the intended site.

- They have to be taken the rest of the way by helicopter,

but they do eventually discover

some really interesting sites.

About 150 tombs, but none of them are Chinggis Khan's.

So, on his second excursion in 2001,

they meet a local herdsman

who tells him about this walled structure

on one side of a mountain,

that's signifying some place of importance.

- As they crest the rise on their climb,

they discover a wall stretching two miles in distance,

reaching heights as high as 12 feet high,

surrounding a mysterious complex.

- [Laurence] In 2002, the Mongolian government

gives Kravitz's team permission to dig.

- Then, trouble hits basically at every step of the way.

Several of Kravitz's team are bitten by pit vipers,

which can be deadly.

They have to be medevaced out.

At one point, one of their cars

rolls off the side of a mountain,

and surprisingly no one is hurt.

There's also an outbreak of anthrax

among some of the animals.

So, at that point,

the Mongolian government decides to shut it down.

- [Laurence] Kravitz is unable to resume the expedition

and dies in 2012.

- There has been no return to that site to explore since,

but whenever you're talking about 800 year old loot

involving a great Mongol emperor,

there'll be treasure hunters from all over the world

who are going to seek this site.

- [Laurence] Chinggis Khan's riches may have been buried

with him according to Mongolian beliefs,

but his tomb has eluded

discovery for nearly 800 years.

- After Chinggis Khan's

death in 1227,

there's a special work commissioned

called "The Secret History of the Mongols,"

that chronicles his life and that of his court.

This was never a text that was meant for public consumption.

This is something that was written

for the private use of those closest to the emperor.

- This document was lost for centuries.

It was originally written in a Mongol dialect,

but eventually since the Mongols later conquer China,

it gets translated into Chinese

and it is rediscovered in the 1800s

in a Chinese version,

which we've been able now to read.

So according to "The Secret History of the Mongols,"

Chinggis Khan is buried in a sacred mountain

in the Khentii Mountain range,

one of the highest mountain there,

some 8,000 feet, called Burkhan Khaldun.

And this is also the place where he was born.

[tense music]

- Burkhan Khaldun actually translates to God Mountain,

so it's a very sacred site to begin with

in Mongolian thinking.

It was a site that was very, very special

to Chinggis Khan himself.

It was a site where early in his life,

he had escaped to find refuge

during a battle that had gone south on him.

He kind of felt this life debt to the mountain itself,

and it was this place where he had returned to often.

In fact, there's one account found

in "The Secret History of the Mongols,"

which says that one day he was out on the plains

there at the foot of the Burkhan Khaldun Mountain,

and there was a solitary tree growing there,

and that he sat beneath its shade.

And while sitting there,

he came to the realization

that this was where he wanted to be buried.

- If Chinggis Khan's wish was honored,

then it's very possible

that not only is he buried there on Burkhan Khaldun,

but some of the treasure could be as well.

In 2009, Albert Lin, an American explorer,

decides he's gonna take a more modern approach

to searching for Chinggis Khan's tomb.

- [Laurence] Using drones and satellites,

Lin and his team collect over 85,000 aerial images

of the Khentii Mountains.

- It's a very large area.

He has 85,000 images,

so he can't do all this himself.

But in our modern age,

he decides that he could bring in

more people through the internet

in a form of crowdsourcing.

Now, these people don't necessarily have to be experts.

They just have to look for things that seem unusual,

that doesn't look natural there,

and he creates an algorithm

for all of the hits that people identify there.

And in narrowing these down,

one spot in particular

on the slopes of the Burkhan Khaldun,

there seems to be a large

man-made structural remains there.

- The only problem for Lin

is that this site is right in the middle

of an area known as the Great Taboo

or the Forbidden Zone.

Almost as soon as Chinggis Khan is gone,

this area becomes off limits

to everyone except for the Mongol elite.

- In fact, it's even said

that it's guarded by a shaman tribe of Mongols

known as the Darkhans,

who protect the area.

This goes hand in hand with this notion

of there being a curse for anybody who disturbs the tomb.

[tense suspenseful music]

- This Great Taboo continues

even during the Soviet rule of Mongolia.

The Soviets don't want anyone

getting hold of Chinggis Khan, his tomb,

any of his treasures that could be used

to spark Mongol nationalism.

It's not until the 2010s

that the Mongolian government

finally allows some in-person research there.

- [Laurence] In 2012, Dr. Lin and his team

are allowed to examine the site

of the stone structure in person.

- They're able to do preliminary digging,

and they do find things like arrowheads

and ceramic pottery shards,

which they're then able to actually date

to the 1200s when Chinggis Khan would've lived.

But unfortunately, the Mongolian government

hasn't granted them permission

to go back and follow up on that dig.

So that mysterious stone structure

remains something of a mystery to us.

- But Lin is not the only one

who's interested in this site.

In 2015, there's a team of French researchers

who use a drone and identify a site

on the side of a mountain at Burkhan Khaldun

that appears to be an ancient mound surrounded by stones.

So this is intriguing,

because it has all the features

of being a potential burial site.

The challenge is that these French researchers

didn't receive the proper approvals

of the Mongolian government,

so the investigation is shut down.

[tense dramatic music]

- Although Burkhan Khaldun seems like

the most likely spot for Chinggis Khan's tomb,

there are still other possibilities.

And in fact, maybe people are working backwards.

We shouldn't think about the tomb first,

maybe we gotta go to Chinggis Khan's death

and start working from there.

- [Laurence] 2016. Yinchaun, China.

American Explorer Alan Nichols leads an expedition

he believes will finally end the mystery

of Chinggis Khan's tomb and treasure.

- Alan Nichols is an attorney and an explorer

who has made himself into somewhat of an expert

on sacred mountains.

So Nichols's idea is to start

with the last information

that we know is true about Chinggis Khan,

which is when and where he died,

and work backwards from there.

[tense dramatic music]

- Nichols instead essentially looks at a map

and he says, "Well, we know where Chinggis Khan died,

and we know that was Chinese territory.

We're relatively certain

that the Mongols would not have buried him there.

However, we also know that the Mongols believed

that burial needed to occur immediately after death,

and as such, they probably would've taken

the most direct route out of Chinese territory

and buried the Great Khan as soon

as it was culturally permissive to do so."

- [Laurence] According to Nichols,

there's another reason why the Khan

would not be buried where historical accounts indicate.

- It's quite possible that there's false information,

deception in these sources,

like "The Secret History of the Mongols,"

because we know that Chinggis Khan himself

was a master of deception.

He used deception frequently in his military tactics.

Besides the feigned retreats and then turning on enemies,

we also know that he would do things

to make the enemy think that his force

was much greater in size than it was.

For example, having his cavalry drag branches

and wood behind them to kick up dust

to make it seem like they had a huge force,

so it was common for him to use deception like this

and so why not to see people about where he's buried?

[tense suspenseful music]

- There is a belief in shamanism

that as soon as you die,

your physical remains can be invaded by evil spirits.

Because he represents the identity

of the Mongolian people,

there would be a special attention made

to an immediate burial for him

to prohibit that from happening.

Nichols believes that Chinggis Khan's army

does not go the distance to take him back home,

but instead goes to the closest place

that is just over the boundary of what is Mongol land.

The land today is inside China,

but at the time, this was Mongol territory.

- [Laurence] In 2016, Nichols claims to have found

Chinggis Khan's likely burial location in Northwest China,

which he refers to only as Mountain X.

- We do know that this so-called Mountain X,

it's in a very modern Chinese city, Yinchaun,

and in addition to ruins of earlier things,

there's also modern structures.

Unfortunately, he won't tell us what that mountain is.

He just calls it Mountain X.

He doesn't want anybody else

to go in there and excavate it

and beat him to the punch,

and get all the glory.

- Applying for permission to dig in such an area

is going to require permissions of the government,

so we have the challenge

of requesting permission to explore a site

that we are simultaneously unwilling to reveal.

The Chinese government says no to further exploration

and shuts this team down.

- [Laurence] Finding Chinggis Khan's tomb

has been an obsession of archaeologists and explorers

for hundreds of years,

but for those focused on locating the treasure,

his tomb may not be the only answer.

- Not all of his treasure might be in his tomb.

After all, the Mongol Empire continued.

In fact, it would continue to expand

even after Chinggis Khan, under his successors

and they would've had to have some wealth

to continue on the empire,

so surely his successors would've retained

some if not most of that wealth.

- We don't have an exact number

for how many children Chinggis Khan produced,

but we're fairly certain that it's well over a thousand.

There is a 2003 DNA study conducted

that suggests that 16 million men on Earth

may have a direct genetic heritage

that can be drawn from Chinggis Khan.

However, in his lifetime,

he only publicly acknowledged four sons

and he determines that the third of those sons, Ogedei,

will be his chosen successor.

- When Chinggis Khan dies in 1227,

he leaves his vast Mongol Empire

to his third son, Ogedei Khan.

The new Emperor, much like his father,

conquers people and territory

with terrifying efficiency.

He expands the Empire west

all the way to modern-day Poland,

but it's Ogedei's transformation of the Mongolian capital

that may hold clues to his father's missing riches.

- The capital of the Mongol Empire was Karakorum,

which is located on the famous Silk Road.

It is the nexus of the East-West trading route.

So Chinggis Khan established this capital

really as a base of operations

from which his armies would go out.

At his time, it was not much more

than a collection of yurts,

but this is going to dramatically transform

under the reign of his son.

- Ogedei unlike Chinggis,

doesn't really see himself

as a nomadic warrior of the steppes.

He's been raised in the environment

that's populated by Mongol power and all of these riches.

And so Ogedei is going to start to look

for more forms of permanence,

and that's going to include the construction

of a massive palace at Karakorum.

- What's really interesting about Karakorum

is that it's not a village that grows gradually

from a village into a town, into a city.

It's essentially like a pop-up city all at once

that Ogedei creates,

and it's meant to be sort of

the jewel of the Mongol Empire,

the place where people from all over can come and visit

and essentially be impressed by what they've accomplished.

- One of the first thing that he does

is he brings in all of the conquered,

captured and conscripted craftsmen

from across the Eurasian continent,

and collectively, they pour their talents

into the construction of this quite glorious capital city.

It was kind of a site of cultural blending

unparalleled at that time.

Walking down the street,

you would see Buddhist temples next to Islamic mosques,

next to Christian churches.

- It is designed to over-awe anyone visits it.

When you start to think about

how you show off wealth and power,

that's what you see embodied in this palace,

and it's where the loot flows back to

because it's important to keep in mind

that Ogedei is still conquering.

He's still expanding the Empire,

so that's probably where a lot of this treasure was.

We have eyewitness accounts showing all of this opulence.

Everything seems to be covered

in gold and silver, ivory and precious gems.

- [Laurence] One of the most detailed accounts of the palace

is written by a visiting missionary

known as William of Rubruck.

- William of Rubruck describes these buildings,

calling them "as long as barns."

He describes these barns as holding treasures,

and if you consider what that means

to a European observer,

you're talking about a vast, long hallway.

[light dramatic music]

- William of Rubruck describes

this incredibly opulent silver and gold fountain

in the shape of a tree,

where literally the tree branches serve as pipes

that can dispense and serve wine, milk, mead.

It's incredible.

Just this fountain alone is a really good indicator

that the Mongols have a lot of precious metals on hand.

- In regards to the wealth accumulated by the Mongols,

while it's doubtful that all of it

was contained in a tomb left for the Great Khan himself,

much of it would've been

brought into the city of Karakorum.

However, the city of Karakorum is kind of

a temporary capital in the history of the Mongol Empire.

- By the 1270s, the Mongols have

abandoned Karakorum as their capital,

basically because it doesn't really have the resources

to support such a large population

and then later on in 1380,

it gets ransacked and destroyed

by a marauding Chinese army.

- For all intents and purposes,

it's no longer a center of imperial power of any type,

it's a relatively small settlement,

but what's left there is destroyed.

Two hundred years after that in 1586,

a large Buddhist monastery is built on the same site.

- In the 1940s, Soviet archaeologists claim

that they have discovered the ruins

of this palace of the Great Khan,

but other experts disagree

and believe that what they found was a temple

and that it's possible that the ruins of the palace

are actually underneath the monastery itself.

The main problem is that the monastery

is still in use today.

They have to get a lot of permission

from the Mongolian government

to actually dig under the site.

[drone whining]

- [Laurence] But technological advances in the 2000s

make it possible to search Karakorum

without extensive digging.

This sparks renewed interest

in the hunt for Chinggis Khan's riches.

- In 2021, German researchers spend fifty two days

surveying the site using something

called super sensitive magnetometry.

It's designed to detect voids and pockets

beneath the surface of the Earth

that might identify previously existing structures.

So if they were able to discern

that this was probably the site of a palace

beneath the monastery.

[mysterious music]

- Archaeologists have discovered

a lot of really interesting artifacts around Karakorum,

including Muslim silver coins,

Chinese pottery, an Egyptian mask,

and even a gold bracelet in the shape of a phoenix.

The main problem is that we don't know

if these treasures are related

to Chinggis Khan's leadership,

or they're just more evidence of Karakorum

as this bustling center of trade.

- The Mongols built great palaces in many locations.

This is not the only one.

If you really wanna make sure

that you have ruled out

every possible location for this treasure,

you've got to go to Xanadu.

- [Laurence] Some believe the key

to finding Chinggis Khan's riches

is to investigate his successors' extravagant palaces,

and none are more impressive

than those constructed by the mighty Kublai Khan.

- Kublai Khan is Chinggis Khan's grandson.

He's actually going to oversee the Mongol Empire

kind of at its height, at its absolute apex.

Kublai Khan is the one that actually

kind of wins the war with China once and for all.

He's obsessed with bringing about the final conquest

of the southern Chinese cities,

that up until the time of his reign

had been able to withstand the Mongol assaults.

- So one of the things

that helped Kublai Khan conquer China

is a new kind of catapult.

The Mongols called it the Huihui Pao,

and basically by having a heavy counterweight,

it can sling a large projectile of some 600 pounds

a good three hundred yards

to smash through enemy walls of fortified cities.

[tense music]

- The Mongols don't just fling stone projectiles

or explosives into Chinese cities,

they will also try to poison the water supplies

by flinging the carcasses of dead livestock over the walls.

They will also fling the heads of their enemies

over the walls.

There's nothing quite like a pile of skulls

to serve as a wonderful message

to anyone who might be thinking

about resisting your conquest.

- [Laurence] With his invasion of China complete,

Kublai Khan now controls 20% of all land on Earth.

- So Kublai Khan inherits the capital in Karakorum,

but because his focus is on

controlling and ruling China,

he wants to build palaces further south,

closer where he can keep an eye on the Chinese.

- So after he conquers China,

Kublai Khan wants to be closer to it

rather than staying in Karakorum.

And so he creates this new capital

some 200 miles away from Beijing.

- There are many experts who believe

that Kublai Khan would've wanted

to bring Chinggis Khan's treasure along with him

to this new capital that he built

to showcase all of the Mongol riches.

Kublai Khan names his new capital Shangdu,

but at the same time,

Marco Polo is working for the Empire as an advisor

and through his accounts,

the name becomes somewhat garbled,

and it's why we now know it as Xanadu.

- Xanadu is this splendid,

wealthy, magnificent place,

a couple of palaces, gardens,

hunting grounds, streams running through it.

In fact, this is what inspired

the famous poem called, "Kubla Khan"

by Samuel Taylor Coleridge,

which starts off with the famous line,

"In Xanadu did Kubla Khan a pleasure dome decree."

- Xanadu is in some ways mythological

and in some ways entirely real.

It's like a Shangri-La,

only we know for sure that it was actually constructed.

Marco Polo claimed to have seen

storehouses filled with treasures

belonging to the Great Khan,

as well as golden and bronze statues in every room.

- [Laurence] Several surviving accounts

document the vast treasure held at Xanadu,

but none of them indicate

what happened to that treasure.

- When Kublai Khan dies in 1294,

there's a lot of infighting among the Mongol successors,

there's a lot of Chinese revolts

and things really go south for the Mongols.

And by 1368, about 75 years after Kublai Khan's death,

the Empire falls.

[fire roaring] [warriors yelling]

- So by 1430, the city of Xanadu no longer

has any real influence.

And as a matter of fact,

the great structures themselves

begin to be reused to build domestic dwellings,

or for other civil purposes.

So the image that we might have of Xanadu is lost to us

because it is incorporated into the next page of history.

[upbeat propulsive music]

- There's really no doubt

that a lot of the loot conquered by Chinggis Khan's armies

continues to amass in the various palaces.

It starts in Karakorum, it winds up next in Xanadu.

That's how empires work.

And as their capital moves,

the riches that underpin it move along with them.

And so it really shouldn't come as a surprise

that when you go to construct a new palace,

you're probably gonna strip the old one

of most of its wealth.

You're gonna reuse a lot of the same materials.

- [Laurence] But the legend of this glittering city lives on.

- The legacy of Xanadu lives on

partly because of Marco Polo's writing,

partly because of the Coleridge poem.

But it's important to remember

that this is not a fictional paradise.

It was a real place.

- We know where Xanadu is.

You can Google map it right now with satellite

and you can see where it is.

There's still a possibility,

with further archaeological investigation,

that something more can be found there.

It's just a matter of what.

[mysterious music] [soldiers chatterng]

- In the 1930s, we know that there are Japanese soldiers

that are using metal detection

as a way of exploring Xanadu,

and they came up empty.

But in many ways, that only contributes to the mystique.

We know that we found clay figures,

things that would be considered great treasures,

but not the kind of treasure that we're talking about

when we say we're looking for the treasure of Chinggis Khan.

- So with no luck so far in Xanadu,

some treasure hunters believe

that we should look a little bit further south,

a few hundred miles down the Silk Road

at another place where Kublai Khan held court.

- Kublai Khan decides that he needs to move his palace

even closer to the centers of power in China.

And so he's going to wind up

building an even bigger palace,

thus outdoing what his predecessors had done.

- [Laurence] Beijing has been China's capital

for over 3000 years,

but in the late 1200s,

it's not the Chinese who control it.

At the time, the city is known as Shangdu,

and is the capital of Kublai Khan's empire.

- Kublai Khan really sees himself

as both Mongolian and Chinese in a lot of ways.

He's adopted many of the mores of Chinese culture,

and so he's going to move

to what we now call Beijing,

and build a massive palace there

as the center point to administer his far-flung empire.

Everywhere you look,

all of the treasure and loot

and inordinate wealth of the Mongols

is within this great palace of Kublai Khan.

- And this is of course Kublai Khan's proudest achievement,

the conquest of China.

So if that's going to be his new capital city,

he's going to bring his treasury with him,

and that again is the inheritance

that goes back to Chinggis Khan.

[propulsive music]

- In 1271, Kublai Khan builds

his most over-the- top palace yet.

In fact, Marco Polo describes this palace

as the greatest palace that ever was.

- Its walls were covered with gold and silver.

It has a dining hall that could seat some 6,000 people,

and then it had private chambers,

according to Marco Polo,

which housed treasures including gold, silver, gems,

and the private property of the Great Khan.

But these were off limits to outsiders,

so who knows how much was in these private rooms?

- The cult of worship that springs up around Chinggis Khan

intensifies under the reign of his grandson, Kublai Khan.

At one point, Kublai Khan

is gonna go so far as to construct

a giant eight-chambered temple

at the palace there at Shangdu,

in devotion to Chinggis Khan himself.

And this was going to become

a site of great ceremonial importance.

In this temple,

he's going to stock it with several relics

that were associated with Chinggis Khan,

along with perhaps jade ornaments and porcelain goods.

- Shangdu is where Kublai Khan settles down

for the remainder of his rule

until his death in 1294.

- After Kublai Khan,

we don't have a clear line of succession.

The Mongol Empire effectively tears itself apart.

Administering this size of an empire

over this wide of an area is all but impossible,

unless you have a very charismatic leader,

a shared common culture,

and a willingness for

the different disparate parts of the empire

to remain together.

And that's just really not the case with the Mongols.

- Given that this is the primary location

of Kublai Khan for over 20 years,

this is a really good potential site

for Chinggis Khan's treasure.

[hooves pounding]

- [Laurence] After the Mongol Empire falls in the late 1300s,

the Chinese retake Shangdu

and according to some accounts,

burn Mongol palaces to the ground.

They renamed the city Beijing,

capital of a new Chinese regime,

the Ming Dynasty.

- They destroy Kublai Khan's Mongol palace

and they set up a new palace center for themselves,

called the Forbidden City.

[mysterious music]

This would be the administrative center

for the royal family of the Chinese Emperor

and his administration,

and it was off limits to everyone else.

The Mongol period is forgotten.

Those buildings were destroyed.

Who knows what happened to them?

- [Laurence] Then in 2016,

archaeologists working in Beijing

propose a startling new theory.

- Archaeologists examining the Forbidden City

find that beneath the palace today are earlier levels.

They find from the more recent Ching period,

that underneath this you have the Ming period,

and below that there is the Mongol period.

So it turns out that the palace of Kublai Khan

is probably there.

It's not near there,

it's actually under the Forbidden City today.

- It's very possible that if we explore these ruins,

that that might be the site

of Chinggis Khan's lost treasure.

But like with a lot of these other sites,

the Chinese government has been

really hesitant to allow digs

underneath the Forbidden City.

For one, its an incredibly important historic site,

and it's a very large tourist attraction.

- If it's the case that Chinggis Khan's treasure

is retained by his successors

and is brought to Beijing

to be in Kublai Khan's palace there,

it's still possible that it's down there today.

But unless a way can be found

to do less invasive archaeological investigation

using modern technologies,

we're in the dark.

We're just gonna have to wait

until that day comes

to figure out what's under there.

- The influence of the Mongolian Empire,

and specifically Chinggis Khan,

is still felt around the globe today.

Chinggis Khan might very well have been

the wealthiest human ever on Earth,

and yet we've found very little evidence

of what happened to his wealth.

- After 800 years,

the lure of Chinggis Khan's lost riches

is still driving explorers

to corners of his vast empire in search of clues.

Archaeologists have uncovered

more ancient burial sites in Mongolia

and a palace in Turkey

belonging to one of Chinggis Khan's grandsons.

Nothing of great value has been found yet,

but treasure hunters can take heart.

There's no shortage of places to search.

I'm Lawrence Fishburne,

thank you for watching "History's Greatest Mysteries."