Original subtitles

The Great Wall of China was built by the Han Chinese

to keep out the nomadic tribes from the north.

They called these people barbarians,

and their lands were considered barren and uninhabitable.

Northern China is indeed a harsh place of terrible winters,

ferocious summers,

parched deserts.

But it is far from lifeless.

With colourful places,

surprising creatures,

amazing people

and strange landscapes.

The further we travel, the more extreme it becomes.

So how do people and wildlife cope with the hardships and challenges

of life beyond the Wall?

The northern limits of Ancient China were defined by the Great Wall

which meanders for nearly 5,000 kilometres from east to west.

The settled Han people of the Chinese heartland were invaded many times

by warlike tribes from the north.

The Great Wall was built to protect the Han Chinese from invasion.

To meet those fearsome northerners and the wild creatures

who share their world, we must leave the shelter of the Wall

and travel into the unknown.

Northeast China was known historically as Manchuria.

Its upper reaches are on the same latitude as Paris

but in winter it is one of the coldest, most hostile places on the planet.

Bitter winds from Siberia regularly bring temperatures

of 40 degrees below zero.

Dense forests of evergreen trees cover these lands.

And the rugged terrain is made even more difficult by impenetrable ravines.

We start our journey on a frozen river

snaking between China's northeasternmost corner and Siberia.

The Chinese call it the Black Dragon River.

The people who live here aren't exactly fearsome warriors.

They're too busy coping with the harsh winter conditions

and they respond to the challenge in some creative ways.

The Black Dragon River is home to one of the smallest ethnic groups in China.

The Hezhe People.

It's not just bicycles that seem out of place in this icy world.

Fishing boats and nets lie abandoned, a long way from open water.

Underneath a metre of solid ice swim a huge variety of fish,

including 500-pound sturgeon,

enough to feed a family of Hezhe for weeks.

But how can they catch their quarry?

First they must chisel a hole through the ice to reach the water below.

Then they need to set their fishing net under the ice,

a real challenge.

A second hole is made, 20 metres away from the first

and a weighted string is dropped in.

Then, a long bamboo pole is used to hook the string

and pull the net into position beneath the ice.

After a few days, the nets are checked.

These days, almost nobody catches a rare giant sturgeon.

The Black Dragon River has been overfished like so many others.

But even these smaller fish are a welcome catch.

Frozen within seconds, the fish are guaranteed to stay fresh

for the wobbly cycle ride home.

The forests that lie south of the Black Dragon River

are bound up in snow for more than half the year.

It's deathly silent.

Most of the animals here are either hibernating

or have migrated south for the winter.

But there is an exception.

Wild boars roam the forests of the northeast.

Like the Hezhe people, the boars find it difficult to gather food in winter.

To survive, they follow their noses,

among the keenest in the animal kingdom.

They will eat almost anything they unearth.

But one energy-rich food source is particularly valued.

Walnuts.

When a lucky boar finds a walnut, there's bound to be trouble.

But despite the squabbles, wild boars are social animals

and gather together in groups.

Staying close together may help them to keep warm in the extreme cold.

But there is another reason for group living.

More ears to listen out for danger.

Siberian tigers also live in these forests.

But these days, only in captivity.

There may be less than a dozen wild Siberian tigers left in China.

Though there are many more in breeding centres.

This enclosure at Hengdaohezi started breeding tigers in 1986

to supply bones and body parts for the Chinese medicine market.

Trade in tiger parts was banned in China in the 1990s

and the breeding centre is now just a tourist attraction.

The forests of the northeast stretch to where the Chinese,

Russian and Mongolian borders meet.

Here, a surprising herd of animals is on the move.

The reindeer were introduced to China hundreds of years ago

by the nomadic Ewenki people who came here from Siberia.

It's late April, and the women are calling in their reindeer,

which are semi-wild, and have spent all winter away in the forest.

This is a very special relationship.

Each reindeer has its own name

and many were hand-reared by these women.

Finally reunited after months apart,

they will now remain together until autumn.

The Ewenki women are anxious to check the condition of their animals

and to see which of the reindeer might be pregnant.

Eighty-one-year-old Maliya Suo is one of only 30 Ewenki people

still living the nomadic life in these cold northern lands.

Almost all her fellow Ewenki have given up the forest life

to settle in concrete houses in modern cities.

The reindeer herders are now almost as rare as wild Siberian tigers.

There's about to be a new addition to the family.

The women act as midwives to the newborn calves,

helping to nurture them through their first precious minutes of life.

But the world around them is changing fast.

This could be the last generation this ancient partnership will endure.

This is hardly the image of the dangerous tribal people

that the Great Wall was built to keep at bay.

Along China's border with North Korea is this region's most famous mountain,

Changbaishan.

Its name means Ever-White,

and it harbours the world's highest volcanic lake.

Even in mid-May there is still ice everywhere.

But there are signs that the seasons are changing.

Warmer winds arrive from the south, and within a few short weeks

Changbai Mountain is transformed.

Water begins to flow down the mountainside once more,

replenishing the landscape.

It's June, and insects emerge to take advantage of the abundance of flowers.

The warm weather sees the arrival of migrant birds.

Stonechats that have spent the winter in the south of China

return here to raise their chicks.

With so many insects around, the stonechats may have several broods.

Heading west from Changbai Mountain,

the forests give way to rolling grasslands.

The Great Wall stretches off into the distance,

defining the southern limits of the vast Mongolian Steppe.

North of the Wall are huge areas of grassland

but one place on our journey is particularly significant.

In the tall grass, a family of red foxes is raising its cubs.

Today they have this meadow pretty much to themselves.

But it wasn't always the case.

Eight centuries ago, this place would have been teeming with people.

Now these ruins in a field a short distance from Beijing

are all that remains of the great city of Xanadu,

once the summer capital of China.

Within these walls it is said that the leader of the Mongolians,

the mighty Kublai Khan, welcomed Marco Polo to China.

Mongolian warriors established the greatest empire in history,

stretching to the borders of Europe.

Fear of this warrior tribe is the main reason

the Han Chinese built the Great Wall.

The cornerstone of the Mongolian's supremacy

was their relationship with horses.

This is what brought them such success in war.

The Mongolian raiders travelled light, and rode with spare horses

so they could move huge distances,

strike and then retreat quicker than their opponents.

At the heart of Mongolian culture is horse racing.

The annual Nadam Festival, held each July,

is a chance for young Mongolians to show off their horsemanship.

It's said that Mongolian people are born in the saddle.

Even as children, they are consummate riders.

Horsemanship was the core of the Mongolians' success

as warriors in the past,

and is central to their lives as nomads today.

In an area of grassland known as Bayanbulak,

families of nomadic Mongolians are gathering.

The name Bayanbulak means "rich headwaters"

and they've come here to set up temporary homes

to graze their livestock on the lush summer pastures.

The search for fresh fodder for their animals keeps them on the go

and being able to move home so easily is a real advantage.

It takes only a few minutes for the Mongolian family

to set up their yurts.

But the Mongolians don't have this place all to themselves.

The rich resources also attract a huge variety of birds.

Demoiselle cranes,

wading birds and waterfowl migrate here from all over Asia,

drawn to the rivers and wetlands fed by glacial meltwater

from nearby mountains.

This place is known in China as Swan Lake.

It's the world's most important breeding site for whooper swans,

and arguably, mosquitoes as well.

The pastures at Swan Lake provide endless amounts of lush grass

for birds to nest in and for livestock to eat.

It would seem there's plenty for everybody.

But occasionally they can get too close for comfort.

Eight hundred years ago,

the Mongolians were the most feared people on earth.

But they have a spiritual side as well.

The birds of Swan Lake have little cause to worry.

The Mongolians protect the swans, and venerate them,

calling them Birds of God.

The Great Wall's journey through northern China continues westward

bisecting a landscape that becomes increasingly parched.

Our journey has brought us halfway across northern China

and the grasslands are becoming hot, dry and desolate.

Wandering these wastes are creatures that look more African than Asian.

These are goitered gazelles, skittish and easily startled.

When threatened by danger, they're as fast as a racehorse.

But in this intense heat, they favour a gentler pace.

There's little standing water here,

but the gazelles have a remarkable ability

to extract moisture from dry grass.

Although finding enough worth eating keeps them constantly on the move.

Even out here in the semi-deserts, the Wall continues its long march.

Here, it's made of little more than compacted earth.

But with hardly any rain falling,

it's suffered very little erosion over the centuries.

Hundreds of thousands of people lost their lives building it.

Yet it seems hard to believe that anyone felt

that these distant wastelands needed protecting.

But the Wall still has one final surprise.

This is Jiayuguan, the mighty fortress in the desert.

Built in the Ming dynasty over 600 years ago,

legend says that the construction of the fortress was so meticulously planned

that 100,000 bricks were specially made

and only one brick was left unused.

This fortress marks the end of the Great Wall of China.

The greatest man-made barrier on earth.

But ahead lies an even more formidable barrier.

A vast no-man's land of deserts that stretch westward

to the borders of Central Asia.

Jiayuguan Fortress was considered

to be the last outpost of Chinese civilisation.

Beyond this point lay utter desolation.

China's largest desert, the Taklamakan, lies out here.

Its name has been translated as "You go in, and you never come out."

This is a place of intense heat,

abrasive wind-blown sand totally hostile to life.

Yet there was a route through the desert.

For those brave enough to risk their lives for it.

People were lured into the horrors of the deserts

because the Chinese had a secret so powerful

that it changed the course of history.

The key to that secret lies in the distant past.

Legend has it that around 5,000 years ago,

a princess was walking in her garden

when something unusual fell into her tea cup.

A magical thread was extracted

and it became more prized than gold or jade.

The thread was silk.

Incredibly, such a beautiful substance and all the history behind it

comes from a humble little insect.

The silkworm.

Silk moths lay several hundred eggs, and the tiny caterpillars that emerge

eat nothing but mulberry leaves.

After 50 days of gluttony

they've grown 10,000 times heavier.

By this stage, 25% of their body mass

is made up of silk glands.

In the process of turning into adult moths, they spin a cocoon

from a single strand of silk which can be over 1 ,000 metres long.

It was the legendary strength and brightness of silk fibres

that made it so sought after.

For over 5,000 years, people built great fortunes

and mighty kingdoms on these delicate threads.

And the desert routes those ancient traders took

became the fabled Silk Road.

The principle of extracting raw silk hasn't changed since its discovery.

Harvested cocoons are dropped into boiling water

which unravels the long filaments.

These are then gathered and spun into raw silk thread.

Here at Hotan, on the ancient Silk Road,

silk weaving is still a cottage industry,

done the old-fashioned way on wooden looms.

For the ancient Silk Road traders,

the problem was still how to get the valuable silk

from the fortress at Jiayuguan

through the deserts to the markets of Central Asia and beyond.

Those early travellers heading west on the Silk Road

were setting off on the worst voyage imaginable

through some of the most terrible places on earth.

Starting with the world's tallest sand dunes.

Strong winds whipping in from the west blow the sand into ever higher dunes.

Over millennia, mega-dunes build up.

Walls of sand soaring to over 500 metres tall.

Camels are the only beasts of burden that can tackle these monstrous dunes.

Their feet are wide and splay outwards to stop them sinking in loose sand.

The wind that whips the sand into dunes

has created other bizarre shapes in China's western deserts.

Mysterious giant structures, known as Yardangs,

were sculpted by flying sand.

The wind brought other hazards to travellers in these deserts.

Marco Polo wrote,

"Sometimes the stray travellers will hear the tramp and hum

"of a great cavalcade of people away from the real line of march

"and taking this to be their own company they will follow the sound.

"And when day breaks, they find that a cheat has been put on them.

"And that they are in an ill plight."

To this day, no one knows what causes the sands

in some parts of the desert to sing.

No wonder travellers call this place Fury of God

and Sea of Death.

But the most severe problem was lack of water.

The reason this place is so intensely dry

can best be appreciated from a satellite view.

China's deserts are the farthest place on earth from any ocean.

This lack of water is what created the Taklamakan.

An area the size of Germany, covered in sand dunes,

through which the Silk Road traversed,

this is the world's largest shifting sand desert.

Most living creatures would die here.

But the camel is uniquely equipped for desert survival.

Its nose humidifies the dry desert air as it breathes in,

then dehumidifies it on the way out, conserving precious water.

The camel's thick fur keeps it warm at night

while reflecting sunlight by day

and its body temperature can rise by six degrees Celsius

before it even begins to sweat.

With these adaptations, it can go for days without drinking.

For the camel trains, travel through the desert is about moving

between one lifesaving oasis and the next.

When they finally do reach a drinking hole,

camels can drink up to 60 litres of water in 10 minutes.

Without oases, life in the Taklamakan couldn't exist

and travel would be impossible.

But nothing is permanent in the desert.

The shifting sands and the extreme climate mean

that these precious water sources can disappear.

This is exactly what happened at Aydingkol Lake.

The lake bed is the second-lowest place on earth

at 154 metres below sea level.

It's the hottest place in China

with air temperatures recorded as high as 50 degrees Celsius

and ground temperatures up to 80 degrees.

Yet not far from Aydingkol is a surprise.

A thriving human settlement in the desert.

This is Turpan oasis.

And it's famous in China for an unexpected product.

Grapes.

But how on earth can a water-hungry crop grow in such abundance in a desert?

The secret lies below ground.

A subterranean network of canals known as karez

is used to channel water around Turpan's streets and into the vineyards.

But where does the water come from?

The clue lies on the desert floor in these lines of holes which mark

the course of the subterranean waterways.

Over two millennia ago, local people carved

more than 3,000 kilometres of these canals

beneath the desert, diverting water from the distant mountains.

Channelling the flow underground

means that less water is lost to evaporation in the desert heat.

In August, the grapes are harvested.

This rich bounty does not go unnoticed.

In the lush vineyards of Turpan, one animal is thriving.

Red-tailed gerbils are hardy desert creatures,

but those in Turpan have never had it so good.

Once the grapes have been picked, some are sold in the market.

But most are hung up to dry in special drying houses.

This place is far too tempting for any rodent to resist.

Red-tailed gerbils are excellent climbers.

But why bother when there's plenty of bounty lying around

on the ground, unguarded?

Rather than suffering the extreme environment in which they live,

the wildlife and people of Turpan have found

innovative ways to cope with conditions beyond the Wall.

But not all desert communities were as resourceful as Turpan.

Between here and China's western borders,

lie the ruins of many great cities.

In their day they were vibrant, thriving places.

But in the 5th century, the Silk Road's fortunes

took a turn for the worse.

Once again a princess was involved.

She smuggled silkworm eggs out of China.

The secret of silk was a secret no more.

And China's stranglehold on this lucrative trade was over.

Even when Marco Polo passed along the Silk Road in the 13th century,

many of these cities had been dead for over 500 years.

But the Silk Road's most famous city managed to survive.

Where the desert ends beneath vast mountain ranges,

China's westernmost point is only a stone's throw from the borders of

five Central Asian countries.

This is Kashgar, where east meets west.

The silk that travelled along the Silk Road ended up here

where it's still traded today.

Kashgar is famous for selling everything under the sun.

The local Sunday market is one of Asia's largest and most exuberant gatherings.

But looking around the market,

it's hard to believe you're actually in China.

Kashgar is a melting pot of non-Chinese ethnic people.

Uyghurs, Tajiks, Kyrgyz, Uzbeks, and many others.

Here, our journey heads northwards into one of China's wildest places.

Leaving Kashgar and the Silk Road behind we travel into the Tian Shan,

or Heavenly Mountains.

This great mountain range defines the border between

China's most north-western province

and neighbouring Tajikistan and Kyrgyzstan.

Its majestic peaks are nearly as high as the Himalayas

forming a natural great wall.

For much of the year it's bound up in ice.

But the glacial meltwater allows evergreen forests to grow.

A far cry from the deserts south of here.

These mountains are the gateway to some of China's

most surprising people and places.

In the upland valleys, a family of Kazakhs

has been grazing their livestock all summer

on the lush alpine meadows.

It's autumn, in a few weeks' time

winter snows will seal the mountain passes.

So the Kazakhs have decided to break camp,

and move while they still can.

Turning their backs on the mountain pastures,

they have many long weeks of travel ahead of them

along well-worn trails.

Their destination could hardly be more different

from the Heavenly Mountains' lush pastures.

These paths head into one of China's wildest and least known places.

This is the Junggar Basin.

An arid land that lies

at the westernmost edge of the great Gobi Desert.

The most northerly desert in the world.

The Junggar is a place of surprises.

This bizarre landscape is called the Five Coloured Hills.

And though very little lives here now,

the ancestors of Tyrannosaurus Rex once roamed these hills,

their fossils only discovered in 2006.

But the Junggar is not entirely lifeless.

In the darkness, a little Roborovski's Hamster

emerges to search for food.

They're the world's smallest hamsters, the size of a Ping-Pong ball.

And they live in family groups of around 10.

Unlike the Kazakhs, hamsters can't migrate to avoid the severity of winter.

They have to prepare for difficult times by storing up provisions

to spend the season underground.

Anyone who has kept a pet hamster

knows what an energetic little creature it can be.

In a single night, a hamster may cover the equivalent

of four human marathons.

But foraging far and wide creates a problem.

How to carry the harvest back to its nest.

Here the hamster's famous flexible cheek pouches come into play.

They can be stuffed full of seeds for carrying back to the burrow.

Underground, the family has special food chambers to store the bounty.

This supply will have to last them through the lean and cold times ahead.

Winter is on its way.

Within a few short weeks, the Five Coloured Hills

are blanketed in snow, driven by icy winds from Siberia.

Despite being at the same latitude as Venice,

Asia's northern deserts have no nearby sea to warm them

and so suffer bitterly cold winters.

When it melts next spring,

the snow will provide moisture for grasses

and other plants to grow.

Like almost everywhere beyond the Wall, the harsh conditions

force people and wildlife to keep moving to find enough to survive.

The Kazakhs have arrived from the Tian Shan mountains

to graze their animals on the meagre pickings in the Junggar.

But the Kazakhs don't have this place all to themselves.

Their winter migration routes take them past a fenced enclosure in the desert.

The horses on this side of the fence

aren't domestic animals like those belonging to the Mongolians and Kazakhs.

These are the last wild horses on earth.

Millions of them once ranged all the way to Europe.

But now they barely number in the hundreds.

For part of the winter the wild horses are quarantined

to stop them mating with the Kazakhs' horses.

That way the gene pool of the rare wild animals can be kept pure.

There is a bigger problem, however.

The livestock and the wild horses compete for the same food.

Many Kazakh families and their flocks will pass through here over the winter.

By the time the wild horses can be released from the pen,

much of the best forage will be gone.

When there's so little to go round in the first place,

it doesn't take much for the situation to turn critical.

Even in the least inhabited parts of China,

wildlife and people come into conflict in the struggle to survive.

Yet in this barren landscape, a remarkable association between

people and wildlife persists.

A tradition harking back almost 6,000 years.

Eighty-two-year-old Ziya carries on a tradition that has made the Kazakhs

famous throughout China.

Every winter for most of his life, Ziya has gone hunting

with a golden eagle.

This eagle is around five years old.

It was taken from the wild as a chick and raised by Ziya

who trained it to return to him after each flight.

He will keep this bird for a total of 10 seasons before setting it free.

Foxes were once the favourite quarry for eagle hunters.

These days they almost never catch anything.

As in many parts of China,

wildlife is far scarcer here than it used to be.

When Ziya finally releases this eagle,

it will be the end of his hunting days.

Many of the younger generation of China's nomads

are moving to modern cities and leaving their traditions behind,

their lives no longer ruled by the changing of the seasons.

Back in the northeast, in mid-winter,

the Great Wall still dominates the landscape.

Originally built to keep out dangerous warriors,

today it is little more than a curiosity.

The Han Chinese, whose ancestors built the wall,

now live in great cities like Harbin, far to the north.

Each year, the artists of Harbin get ready for a special winter celebration.

Giant blocks of ice from nearby rivers undergo a magical transformation.

Tourists flock to Harbin from all over China

to see the spectacular carvings,

and the ice city that has sprung up all around.

It takes 10,000 people 18 days to construct this icy wonderland.

It's impressive enough by day.

But the magic of this place only becomes apparent once the sun goes down.

Northern China can be a harsh place, but also a place of great beauty.

The Harbin Ice Festival shows how attitudes have changed

since the Great Wall was built.

No longer are the extremes of life beyond the Wall merely to be feared.

Now it is possible to celebrate them, too.