Original subtitles

ALLAN [off-screen]: Inner Mongolia, China.

I'’m here on the trail of a 750 year old legend,

that began with tales brought home,

by an intrepid European explorer.

ALLAN: The main reason I'’ve come here is because of this book.

These are the accounts of the travels of Marco Polo.

"There at this place is a very fine marble palace.

The rooms of which are all gilt and painted with figures

of men and beasts and birds all executed with such exquisite art,

that you will regard them with delight and astonishment."

What he'’s talking about here is the great fabled city of

Kublai Khan, the grandson of Genghis,

Xanadu.

ALLAN [off-screen]: Now with the help of new technology,

I'’m out to discover if Marco Polo'’s descriptions of such an

astonishing city can really be true.

I'’m Allan Maca.

An archaeologist and expert in ancient civilizations.

And I'’m investigating China'’s distant past

from a whole new perspective...

space!

Today, state-of-the-art satellites see the world

in stunning detail.

And reveal hidden archaeology, enabling us to recreate a lost

ancient world, invisible to the naked eye.

Working alongside leading Chinese experts,

my team and I are traveling to some of the country'’s most

remote and incredible landscapes,

and with cutting-edge science, investigating previously

unknown cultures, lost cities and devastating cataclysms.

This is ancient China as you'’ve never seen it before.

The vast Steppe of Inner Mongolia.

An open grassland in one of the largest and least

populated regions of China.

And, if Marco Polo is to be believed,

this wide-open wilderness once contained one of the greatest

cities on the planet.

Two centuries before Columbus sailed for the Americas,

Marco Polo travelled from Europe along ancient trade

routes, to explore the distant lands of the East,

keeping detailed journals as he went.

In 1275, he arrived at the gates of a great city,

Kublai Khan'’s Xanadu.

Today, the only clues left on the ground

are a series of mysterious mounds rising from the plains.

ALLAN: There'’s just a lot of grassland,

just a lot of empty space, it'’s hard to imagine that

there could ever be a city here.

I'’ve been hearing about Xanadu all my life.

As an archaeologist I'’ve studied and taught these

periods but I'’ve never been here.

ALLAN [off-screen]: Now I'’m going to explore the mystery

of Xanadu in a whole new way.

ALLAN: Wow. Amazing!

RYAN [off-screen]: Yeah it really sort of pops...

ALLAN [off-screen]: With cutting-edge technology,

can we bring this legendary city back to life?

ALLAN: Look at this thing.

This is a wild image!

ALLAN [off-screen]: Scouring China for clues,

what can we discover about the man who ruled over a quarter

of the world'’s population?

JENNY: This is much bigger than I expected.

ALLAN [off-screen]: And how was Beijing,

one of today'’s great megacities,

born from Xanadu?

ALLAN: I think we'’ll get a great point of view from up here.

What an expanse.

ALLAN [off-screen]: Close up, it'’s clear these mounds are man-made.

ALLAN: Sighting straight down this east-west wall-line.

It'’s a perfect 90 degree angle.

This is cool.

ALLAN [off-screen]: But could Xanadu really have been as

magnificent as Marco Polo described?

A great medieval city filled with astonishing architecture

and lavish palaces?

Down on the ground, these ruined walls don'’t tell us much.

But from space, 500 miles up...

The shape of this lost city is revealed.

The remains of a series of massive walls.

Each one guarded by gates and corner watchtowers.

The outer wall runs for 5 and a half miles enclosing an area

at the time, even bigger than London or Paris.

And right in Xanadu'’s center, the faint outlines of buildings.

Chinese Archaeologists have surveyed and excavated this

central area, but since becoming a protected site,

further digging is restricted.

Yet, there are other ways for us to investigate.

Researchers Ma He, Xi Yaqing and Ma Qinglong from Peking University

are being joined by Eric Lo and Ryan Kastner from

my tech team.

Together, they'’ll use hi-tech sensors on drones to conduct a

whole new survey of central Xanadu.

ERIC: So what I'’m putting on is a multispectral camera

which sees in other bands beyond the visible red, green and blue

that we normally see and we'’re hoping

that this will see some anomaly,

that might indicate there'’s been a structure there in the past.

ALLAN [off-screen]: While the multispectral camera looks for

signs of buildings beneath the surface.

A second drone captures hundreds of images to create a

detailed 3D model of everything above the ground.

ALLAN: Hey, what'’s up, guys?

ALLAN [off-screen]: With the results in,

I'’m going to take a look with Xanadu expert, Bao Lige.

ALLAN: What have you got?

RYAN [off-screen]: With the drone imagery you can see a tremendous amount

more detail than you can see with the satellite imagery.

So you can see some of the structures and obviously the roads.

ALLAN [off-screen]: And elevation data from the second drone,

reveals every slight bump on the ground.

Oh neat, wow! Amazing!

RYAN [off-screen]: Yeah it really sort of pops.

BAO: Look at that, it'’s really really clear!

ALLAN [off-screen]: And look at all these buildings,

I mean there'’s a lot going on here.

RYAN [off-screen]: Yeah you can clearly see a bunch of different types of structures.

ALLAN [off-screen]: Straight lines mean man-made structures

like walls and roads, and boxes give us the outlines of buildings.

Revealing these features in the central zone,

combined with historical records allows us to recreate

the very heart of Xanadu.

A dense concentration of streets and buildings.

Most prominent of all, three mighty structures.

Chinese experts have identified these as Kublai Khan'’s palaces.

BAO: This whole Palace City is arranged along the central axis,

it'’s a very well-established layout.

ALLAN [off-screen]: The largest palace is in the north,

this was the Mu Qing Ge,

Kublai Khan'’s residence and a place for official business and banquets.

There'’s little known about how it looked,

but Chinese Archaeologists have discovered elaborate roof

ornaments and beautiful glazed tiles that give us a glimpse

into its magnificent past.

From these grassy mounds, technology is revealing that

Marco Polo'’s descriptions could really be true.

But why is Xanadu here at all,

in the middle of this remote wilderness?

The city was built by Kublai Khan from scratch in 1256.

He was the grandson of one of history'’s most famous warlords,

Genghis Khan.

50 years earlier, Genghis Khan had united the nomadic tribes

and established a vast Mongol Empire,

including conquering most of the Dynasties that,

back then, ruled China and taking control of their

largely Han Chinese population.

But the south, ruled by the Southern Song Dynasty,

remained unconquered.

After Genghis Khan, the Empire was divided into

Mongol Kingdoms called Khanates and in 1251 Kublai Khan took

charge of what today, is Inner Mongolia.

He was determined to establish a new dynasty that he'’d call

the Yuan, defeat the Southern Song,

and bring all of China under his rule as one all-powerful Emperor.

But first he needed a secure base from which to unleash his campaign.

The City of Xanadu was born.

I'’ve seen how the center of Xanadu was full of palaces.

But what lies beyond these inner walls?

To find out, we need to go back to the satellite images.

Archaeologist Sarah Klassen, from my tech team,

is taking a closer look at the wider city.

SARAH: I can see quite a few faint impressions on the land

that might be related to archaeological features like

streets or buildings.

Let me see if I can enhance this image.

Oh wow, look at this, this is pretty neat.

ALLAN [off-screen]: Using infra-red,

Sarah can spot differences in how the vegetation'’s growing,

that indicate man-made structures,

hidden just beneath the surface.

SARAH: So all of those faint impressions that I saw before

are now very visible on the landscape.

ALLAN [off-screen]: These infra-red satellite images

combined with Chinese archaeological evidence and

historical records, reveal the whole walled city of Xanadu in

stunning detail.

Not just its palaces, but hundreds of buildings.

Courtyards and compounds.

Defensive towers and grand gateways.

An incredible megacity.

Marco Polo'’s descriptions are so far proving right,

but there'’s a mystery, because he described another palace

that doesn'’t show up.

With a golden roof and lacquered pillars,

experts believe it was a vast circular building.

Just what was it?

And can we find it?

ALLAN [off-screen]: I'’m trying to solve the puzzle of a huge

lost circular palace that Marco Polo said was one of the

wonders of Xanadu.

Could its circular shape indicate a special type of

Mongol building that'’s still in use today?

I'’ve been invited by Enkh Bayr and his family to help out

building a traditional Mongolian house, a ger.

ALLAN: You can see that it'’s a latticework pattern made from willow tree.

And these are thicker willow posts that hold up this

central structure, that also can have a slight opening

because of course, there'’s going to be a cooking fire in

here as well, and then you'’ll sleep over here on the other side.

ALLAN [off-screen]: These simple round structures are

the key to a nomadic lifestyle;

light and easy to assemble, they'’re quick to pack up and

move on to new pastures.

ENKH: I'’ve grown up in Mongolian Gers since I was a child.

I feel very comfortable sleeping in one.

They are well-ventilated and very cozy.

ALLAN [off-screen]: This tough nomadic culture is the world

that Kublai Khan came from.

Could his Mongol roots shed light on one of Marco Polo'’s

most vivid descriptions?

ALLAN: He says, "The whole palace is built of these canes.

The construction of the palace is so devised that it can be

taken down and put up again with great celerity and it can

all be taken to pieces and removed withersoever the

Emperor may command.

When erected, it is braced against mishaps from the wind

by more than 200 cords of silk."

So imagine the size of this thing.

Could it have been a ger?

A monumental ger?

An imperial sized ger?

ALLAN [off-screen]: Now, using Marco Polo'’s description and

other historical sources, we can recreate what

Kublai Khan'’s palace of canes might'’ve looked like.

ALLAN: Look at this thing.

This is huge!

This is a wild image.

ALLAN [off-screen]: Circular like a ger,

with a varnished golden roof made of bamboo canes.

It would'’ve been supported by lacquered and gilded pillars

decorated with dragons

and stood as high as a ten-story building!

This moveable palace hosted lavish banquets for over 2000 guests.

Even after more than 750 years,

surely something this huge would have left some trace.

If our drone images failed to detect it,

would it help to look from space?

SARAH: When I look close at the palace area I can see a

ton of features on the landscape and even kind of

beyond that until the second city wall.

And the northwest is really interesting

'’cause I don'’t really see even

faint impressions of archaeological features.

I would'’ve thought that this whole area within the city

walls would'’ve been taken up with buildings and streets.

ALLAN [off-screen]: This large empty space seems strange,

but during the years he spent at Kublai Khan'’s court,

Marco Polo said he saw a great park,

stocked with wild animals, to satisfy a favorite Mongol

pastime, hunting.

And he wrote that the cane palace stood in a grove within

these hunting grounds.

Guided by the satellite imagery,

the drone team moves in to take a closer look.

RYAN: We think we might have found something interesting in the outer city.

You can see...

ALLAN [off-screen]: Oh yeah, oh yeah!

RYAN [off-screen]: Yeah it'’s...

ALLAN [off-screen]: Most of Xanadu'’s structures were built

on platforms to keep them clear of wet ground.

If a base had also been laid for the cane palace,

it might have left a circular trace.

ALLAN: We walked all over this;

we didn'’t see that from the ground at all.

RYAN [off-screen]: Yeah it'’s hard to actually see any of this

stuff, that'’s why the drones or the bird'’s eye view really

gives you a nice perspective.

ALLAN [off-screen]: Well the east side of this thing

very clearly looks like half of a circle.

RYAN [off-screen]: Yeah.

ALLAN: It does, it definitely does.

ALLAN [off-screen]: Could this really be it?

A faint impression of Kublai Khan'’s amazing cane palace?

ALLAN [off-screen]: I'’m hunting for evidence of one of

the great lost wonders of Xanadu.

A vast moveable palace.

And my tech team has found something.

RYAN [off-screen]: This is the digital elevation model,

so the colors indicate the height,

how high or low, off the ground these are.

ALLAN [off-screen]: Could this be the raised platform that my

team is looking for?

RYAN: It'’s indented so it'’s a little bit more red here,

so you can see it'’s a depression, it'’s a crater of some sort.

ALLAN [off-screen]: Yeah very clear.

RYAN: Yeah it'’s a very clear depression.

ALLAN [off-screen]: Sadly, it'’s not the relic of a raised

platform, but Mr. Bao has another theory.

BAO: For this kind of palace, maybe they lifted the whole platform

up and away on wooden poles.

Or it was a large-scale imperial carriage with a

temporary palace on top.

ALLAN [off-screen]: If Mr. Bao is right,

Kublai Khan'’s amazing golden-roofed,

imperial ger, really was a temporary structure with no

permanent base, in true nomadic Mongol style.

So for now, exactly where it stood remains a mystery,

but the satellite data are revealing other secrets.

Sarah'’s spotted something even further out,

past the hunting ground and the outer walls.

SARAH: If I look beyond the walls,

of the city, I can see some faint impressions.

Take a look at that.

So, there are actually buildings and roadways that

extend beyond the walls of the city.

ALLAN [off-screen]: If these date to Kublai Khan'’s Yuan dynasty,

then Xanadu even stretched far beyond its city walls.

And out in this wider sprawling city,

huge, intriguing structures.

I'’m heading east beyond the outer city walls to

investigate, with Xanadu expert, Bao Lige.

BAO: We are at Xanadu'’s Little East Gate on the main road

that goes through it.

During the Yuan Dynasty this eastern suburb served as a

place for the nobility to stay when visiting the Great Khan.

ALLAN [off-screen]: It explains the impressive walled

compounds revealed on the satellite images.

And Chinese research also reveals there were sprawling

suburbs beyond the city walls on every side,

with evidence of military barracks,

markets and guesthouses.

And right on the edge of the suburbs there are also two

enormous and identical structures.

What are they?

ALLAN: So we'’ve got some really interesting buildings here.

What do you know about it, what can you tell us?

BAO: In the Yongle Classics, it'’s recorded that Xanadu had

two granaries, one in the west and one in the east.

They measured 150 meters wide and 290 meters long.

ALLAN [off-screen]: That'’s the size of 10 American Football fields.

BAO: There wasn'’t anything else on this scale in other

areas, or here in the eastern suburb.

ALLAN [off-screen]: All the evidence points to this being

one of Xanadu'’s vast grain stores.

To explore it in detail, the Peking University tech team gets to work.

ALLAN: Can we look really closely at this area you scanned?

Oh wow!

RYAN [off-screen]: You can clearly see the different structures.

ALLAN [off-screen]: Combining our scans with historical

records, reveals this granary isn'’t just one large barn,

it'’s an entire complex.

BAO: I think each different type of grain would be stored separately.

This big area in the middle, you could call it a courtyard.

You could take out grain that hadn'’t been used up and re-dry

it in the sun before storing.

ALLAN [off-screen]: Now, knowing the layout of this

granary, can our scans help solve an enduring mystery.

Just how many people lived in Xanadu?

ALLAN [off-screen]: I'’m investigating the remains of a

granary far outside Xanadu'’s city walls,

to see if it can answer a crucial question.

ALLAN: I'’d be really interested if we can come to

some sense of what was the population of the city at that

time, by estimating volume of grain storage,

against what people would have needed.

BAO: At that time, each person would have needed

180 kilograms of grain per year.

ALLAN [off-screen]: Using our model and Chinese research,

we can now estimate how much grain this granary could'’ve held.

ERIC: Based on these calculations we could store

21 million kilograms and so we can see that we'’d have an

approximate population that we could feed of 120,000 people.

ALLAN: Wow, that'’s really substantial.

If you consider that London in the 13th century only had

about 80,000 people that says that this was a really

substantial city.

ALLAN [off-screen]: Even though these figures are based

on rough estimates, they'’re for just one of two granaries

at Xanadu, which would mean the potential population could

be more than 200,000 people.

Almost twice the size of Marco Polo'’s home city of Venice.

It'’s no wonder Marco Polo was blown away by what he saw here,

and he must have noticed that unlike the winding streets

of mediaeval Europe, Xanadu was built to a precise plan.

The city is aligned along a North-South axis.

And even its location was carefully chosen.

ALLAN: This was geomantically designed.

So it'’s laid out in relation to geological features of the landscape.

ALLAN [off-screen]: Protected by mountains to the north and

with a river to the south, this is an ideal setting for

Han Chinese city builders.

ALLAN: We have a city built here by nomadic peoples from the north.

And it'’s incredible that Kublai Khan,

as a hereditary Mongol emperor,

is using ancient Chinese principles to design his city.

ALLAN [off-screen]: Kublai Khan even had a Han Chinese Advisor

draw up the plans, giving it the square concentric walls

and central palace area.

ALLAN: This is a classic Han Chinese city plan.

ALLAN [off-screen]: In building a permanent walled city,

with a hunting ground and imperial-sized ger,

combined with a Chinese layout,

Kublai Khan was embracing both his Mongol roots and

Han Chinese culture.

The question is why?

And was this blending of cultures happening elsewhere,

beyond the walls of Xanadu?

680 miles to the south west, in the ancient city of Xi'’an,

a clue has been discovered in a tomb that could hold the answer.

Dr Chao-Hui Jenny Liu, our expert in classical Chinese

art and archaeology, is meeting Excavation Leader Miao Yifei and his team,

who are analyzing this 700 year-old work of art.

JENNY: Here it is, the mural.

[speaking Mandarin].

Wow.

ALLAN [off-screen]: This mural once lined the curved walls of

a lavish circular tomb.

JENNY [off-screen]: This is much bigger than I expected.

This is amazing.

MIAO: Once I'’d properly entered the tomb,

I was totally stunned.

This was so beautiful, I was astonished,

really surprised.

JENNY [off-screen]: It'’s amazing.

Here you have six people sitting on this,

sort of a bed with a screen in the back.

And the center person, we think it'’s the husband,

is wearing Mongol clothes.

We see this kind of clothes also on portraiture of Kublai Khan.

There'’s a white robe and then this kind of red hat,

very typical of Mongol clothes.

ALLAN [off-screen]: But closer inspection of these

traditionally Mongol images, reveals some surprising details.

JENNY: This is a hunting scene,

where the hunter is shooting an arrow at the doe,

but there'’s a little man underneath here, you see?

And he is milking the doe, so it completely changes the

picture because a hunting scene would be Yuan Dynasty or

Mongol, but this story where a good son milks the doe to give

milk to his parents, that'’s a Chinese story.

This mural shows that the mixing of cultures, Chinese culture,

Han culture, Mongol, Yuan culture,

they become one, and you cannot separate them.

ALLAN [off-screen]: It seems the mixing of Mongol and Han

Chinese cultures was not just happening in Kublai Khan'’s city;

it was spreading far beyond Xanadu.

And this was all part of his plan.

He knew he had the military might to conquer the rest of China

but to keep control, he'’d need to win hearts and minds.

ALLAN: It reminds me of something that the legendary

Chinese advisor of Kublai Khan supposedly said to the great

Emperor, he said, "Look you can conquer a land by horseback,

but you can'’t administer a land by horseback."

ALLAN [off-screen]: Embracing both cultures was

Kublai Khan'’s key to success.

And this plan began right here with Xanadu.

They designed a city, so that they could control the

population, keep them happy and administer things.

Not in the way that Mongol horse nomads would,

but the way agricultural Han Chinese would.

Xanadu was Kublai Khan'’s power base.

And Marco Polo described one building that was the very

heart of operations, a palace called the Da'’an Ge,

the Pavilion of Great Peace.

The platform that we see today is not the only trace that remains.

ALLAN [off-screen]: Kublai Khan'’s Pavilion of Great Peace

once stood at the very heart of Xanadu.

Only rare fragments of Xanadu'’s palaces have survived.

But in 2003 Chinese Archaeologists unearthed

something astonishing.

ALLAN: Wow. Here it is.

This is the legendary marble pillar from the Da'’an Ge Palace complex.

Look at how big this thing is.

The carving is exquisite.

You have flowers here, which are symbols of auspiciousness

and good fortune.

You'’ve got the dragon.

Look at it, twisting around all the way to the tail.

ALLAN [off-screen]: In Han Chinese culture,

the dragon is a symbol of imperial power and typically

had 3 or 4 talons, but this one is different.

ALLAN: So here we have five talons and a smaller head,

smaller than we see in dragons from earlier dynasties.

We have a horse nomad asserting himself as a great Chinese emperor.

People looking at this, they would have known that this is

Kublai Khan himself.

He is the dragon, telling the world,

I am the head of a new Chinese dynasty,

the Yuan dynasty.

ALLAN [off-screen]: Now, by combining recent Chinese Academic Studies

with our drone surveys of central Xanadu,

we can bring Kublai Khan'’s magnificent Pavilion of Great Peace

back to life, for the first time in over 650 years.

ALLAN: Woah, this thing was big!

Ah incredible, incredibly beautiful.

I mean, there'’s no question looking at this,

that the Da'’an Ge was a classically Han Chinese building.

ALLAN [off-screen]: The Da'’an Ge sat on a raised central platform.

Supported by huge marble pillars this great palace was

taller than a modern 22-storey building.

This was the site of Kublai Khan'’s throne,

the "very fine marble palace" that astonished Marco Polo.

I'’ve explored Kublai Khan'’s great palaces,

but the satellite images also reveal other prominent

structures among the hundreds of buildings.

Their layout suggests these are not palaces,

but temples.

But Mongols traditionally practice Shamanism with no

need for temples.

So what'’s going on?

Almost 900 miles west of Xanadu,

close to the city of Zhangye, Jenny is searching for answers.

These sheer cliff faces hold something very special,

an incredible complex of ancient Buddhist temples,

carved deep into the rock.

Buddhists started carving these shrines centuries before

Kublai Khan'’s Yuan Dynasty.

But what then?

Throughout history, many invaders wiped out the sites

and shrines of existing religions.

But here at the Ma-Ti Grottoes.

JENNY: Wow, look at all these niches!

ALLAN [off-screen]: Jenny'’s noticed something surprising.

JENNY [off-screen]: The structure of it, the archway,

this is largely of the Yuan Dynasty style.

ALLAN [off-screen]: Everywhere, signs that the carving continued under Kublai Khan.

JENNY: The dress and also the hairstyle,

the very peaceful, calm expression on the face,

the Lotus seat too is very typical of the Yuan period.

ALLAN [off-screen]: This shows that Buddhism didn'’t just

survive under Kublai Khan, it thrived!

And back in Xanadu, Li Hailiang,

Director of the Xanadu Museum has evidence that suggests

this went far beyond just Buddhism.

LI: This artifact is a tomb headstone,

it'’s got Islamic texts carved on it.

The Yuan Dynasty implemented an all-embracing policy

towards all religions.

This kind of freedom of belief was unprecedented,

so they could build lots of temples in Xanadu at that time;

Buddhist ones, mosques, Nestorian Christian churches

and so on.

So now we locals call Xanadu '’the 108 temples.'’

It reflects very lively thinking in Yuan Dynasty society.

ALLAN [off-screen]: Combining our scans with historical records,

reveals that these two buildings were Buddhist temples.

But they were just two of dozens of religious buildings

including mosques, Daoist temples and Confucian shrines.

By design Xanadu was a melting pot where different peoples,

philosophies and religions all came together.

A city every bit as vibrant and cosmopolitan as Marco Polo described.

From where, Kublai Khan could now launch his master plan,

to conquer all of China.

ALLAN [off-screen]: In 1260, Kublai Khan'’s new capital,

Xanadu, became one of the most important cities on earth.

Kublai Khan was named the next Great Khan,

with power over Mongol Khanates that now reached from

today'’s Far Eastern Russia, all the way west to Turkey and Ukraine.

But, he still needed to conquer the Southern Song Dynasty.

To achieve his goal, he planned another city,

a second capital closer to the Chinese heartland.

Today, Xanadu'’s sister city, known as Dadu,

lies hidden 170 miles south, deep beneath the streets of a

very modern megacity.

Beijing.

Now home to over 20 million people,

it'’s more than twice the size of New York City.

750 years ago, Marco Polo'’s adventures also brought him

here, to the newly created Dadu.

He wrote that it'’s palace was so vast,

rich and beautiful that "no man on earth could design

anything superior to it."

In 2016, the foundations of Kublai Khan'’s palace were

discovered beneath Beijing'’s famous Forbidden City,

lost traces of the imperial heart of Dadu.

Now Sarah has come here to see if satellite images can reveal

any more of Kublai Khan'’s second capital.

SARAH: Oh wow, this is really interesting.

ALLAN [off-screen]: About 5 miles north of where Dadu'’s

palace once stood, Sarah'’s spotted something,

an unusual line of trees.

Down on the ground, it starts to make sense.

SARAH: Alright, so this is what I'’ve been looking for.

So we'’re on this large mound, linear mound in the middle of this city.

It looks like it'’s definitely manmade.

You can see that where I'’m standing,

it'’s actually part of this longer linear embankment and

it actually looks like it forms a square around the city.

ALLAN [off-screen]: Chinese research confirms,

this is part of an original city wall of Dadu.

SARAH: It'’s pretty incredible, that something this old is

still in the middle of the city of Beijing and hasn'’t

been destroyed over hundreds of years.

ALLAN [off-screen]: Adding this city wall to the

satellite image along with data from historical maps

reveals something amazing.

Beijing'’s modern streets still align with Dadu'’s city walls,

as if Kublai Khan'’s capital was the blueprint for this

21st century Metropolis.

SARAH: So the similarities between what we can see here

at Dadu and what we saw at Xanadu are incredible.

ALLAN [off-screen]: Kublai Khan had taken the Classical

Chinese design of Xanadu, and supersized it.

Dadu was ten times bigger.

From Dadu Kublai Khan could

strike out south and by 1279 he'’d achieved his goal.

For the first time in over 350 years,

the nation was reunited.

Kublai Khan was finally Emperor of all China.

Kublai Khan'’s incredible vision allowed this Mongol

ruler to found a new dynasty, that was accepted by the

Han Chinese people of his Empire.

Under his reign, China thrived.

He extended trade routes to reach half way around the globe,

and poured resources into China'’s infrastructure,

making its Grand Canal the longest anywhere in the world.

With Dadu, he'’d laid the foundations for what is today,

one of the greatest cities on earth.

And it all started with the wonder of Xanadu.

ALLAN: I came here wondering if Marco Polo was kind of

pulling our leg, you know, exaggerating or maybe even

like that this was just all the raving fantasy of some mad Italian.

And I'’m satisfied that what Marco Polo was telling us

was not some kind of a myth, he was really giving us a sense of

reality that he saw with his own eyes.

Now, new technology is finally revealing Kublai Khan'’s

astonishing city of Xanadu.

Carefully planned and beautifully constructed,

it was both Mongol and Han Chinese,

and on a magnificent scale.

Xanadu really was a vibrant, cosmopolitan capital,

a cultural melting pot, filled with amazing temples and

stunning palaces, fit for an Emperor who ruled over a

quarter of the world'’s population,

and the biggest empire on earth.

ALLAN: What we now know is that Marco Polo was absolutely right,

Xanadu was spectacular.

Captioned by Cotter Captioning Services.