Episode 1 Down the Mighty River with Steve Backshall

This programme contains some strong language

Look at this place! Simply breathtaking.

Welcome to New Guinea -

the world's largest jungle island.

One of the most remote and unexplored parts of our world.

It's very intimidating, potentially very dangerous,

but also one of the most exciting places on the planet.

Running from its mountainous heart over 500km,

through pristine wilderness,

wild gorges and tropical jungle out to the sea...

..is the mighty Baliem River.

I was expecting it to be big...

..but I wasn't expecting that.

No-one has ever travelled the full length of this untamed river before.

We've managed to turn a simple side trip into an absolute epic.

I'm Steve Backshall, I'm a naturalist and adventurer.

It just looks like there should be dinosaurs everywhere.

I want to explore the river and discover more about the remarkable

variety of worlds through which it travels.

Ow, shoot!

It is home to ancient tribes.

I want to see how they are coping with the modern world.

When they are in mourning they will cut off their own fingers as a sign of grief.

I will be searching for some of the world's scariest animals...

'It was basically eating its way through the village.'

..and exploring a vast, uncharted underground world.

Now that is impressive.

But the Baliem is so inaccessible, that the only way to uncover

its secrets is to travel its length from source to sea...

We are committed now.

..by any means possible.

It could give us a unique insight into one of the last truly

wild places on Earth. Where the hell are you taking us?

Or it could be a journey...

..too far.

SCREAMING

Oh, wow, look at that!

That is just gorgeous.

It is the first day of our five-week expedition in New Guinea to travel

the length of the Baliem River.

It is located in the province of Papua,

the western half of the island of New Guinea.

It was once a Dutch colony but now it is part of Indonesia.

Just knowing that there are huge areas here that are

still unexplored, undiscovered, even now in the 21st century,

just sets the hairs up on the back of my neck -

that kind of sense of expectation of what might be ahead.

Our journey begins 3,500 metres above sea level

in the central highlands.

Running for over 1,600km,

this mountain range is longer than the Alps,

and is one of the wettest places on the planet.

There it is!

That is my first sight of Lake Habbema.

This 5km-long lake is where the Baliem River begins its life.

Below us now are incredible, high-altitude montane forests

and there is nothing there apart from the odd river kind of twisting

and turning in between them.

Our 500km journey will start in the wild

central highlands and end at the Pacific Ocean.

In this first part of the expedition we are aiming to kayak through

deep, dark gorges, and explore giant caves,

before reaching the Baliem Grand Valley,

a land inhabited by the ancient Dani people.

We've landed a few kilometres from Lake Habbema,

where the water is just deep enough to launch our kayaks.

I don't think any of us expected it to be this special.

It is beautiful, it's absolutely stunning.

It is beautiful, it's pristine and the river is clear.

But what lies ahead is unknown.

So there are no decent maps of where we are right now.

All of the sort of research that we have done about this area

has been from satellite imagery.

All of a sudden, it's real.

All we do know is that for the next 15km,

we will be heading into a series of uninhabited, steep-sided gorges.

Ex-marine commando Aldo Kane is our safety expert.

This gives a bit of a wrong impression of what is probably

going to be coming up as well with the amount of drop and descent

that we've got between here and the bottom of that gorge.

To stand a chance of pulling off this daring adventure,

I've put together a team of some of the world's top expedition kayakers

and rafters led by New Zealander Jordy Searle.

This is going to be a challenge.

You know, anywhere that has never been charted before and that we

know nothing about, there is always challenges.

The film crew and support team are following in an inflatable raft.

I do believe in my heart that this is one of the greatest expeditions

there is left to do on the planet.

You know, it has everything.

Finally, we're on the Baliem River.

Yeah, boys.

Heading downstream...

..500km to the sea.

Around us, the plants and trees are adapted to living at altitude.

And for the moment it is just running nice and easy,

nice and gentle, just a lovely way to get started.

The peace and tranquillity up here is just extraordinary.

And all of the trees are covered in moss which kind of deadens

all the sound.

It is just silent.

Ahead of us we're just starting to get the landscapes steepening

and this could well be the beginning of that gorge.

This upper section of the river winds its way over glacial deposits...

..but when it hits the limestone bedrock,

it changes character abruptly.

Over millions of years, water has percolated through cracks

in the limestone, forming caves and passages.

When these collapse, they leave behind debris-strewn gorges

like this one.

Wow!

We are kayaking through what could have once been an underground

cave system.

So we are in the gorge

and it is utterly spectacular.

Very, very steep-sided.

We are committed now.

As the river enters the gorge, the narrowing of the cliff walls

forces the water to flow faster,

and we hit our first rapid.

I started kayaking when I was 12...

..and I paddle some big rivers,

but this will push me to my limits.

-Sharp rocks to the underside of the raft, you know.

-Yeah.

The erosion is ongoing,

so fresh rock falls keep filling the riverbed with more jagged rocks.

Stay here.

'It is bad news for us.'

This is our first big rapid.

'Especially our boats.'

The boys are going to go ahead and scout.

Let's see if we can bring the raft down.

Our plan for running rapids is to send safety kayaker Barney Young

ahead, so he can scout a line through the white water.

Then I will follow with Jordy and David Bain.

OK, Steve. Go.

-All good?

-Yeah, all good.

I've got to try and follow the fast flow line down the left-hand side.

But it is taking me close to the jagged limestone cliff.

Too close.

I've nearly torn the bottom out my boat already.

Up, up, up here.

Up, up, up.

Nice, mate.

We are through our first rapid.

But there's a lot worse to come.

-Yeah, that's good paddling.

-Thank you.

And you know that compliment's real, cos I don't compliment poms easily.

HE LAUGHS

Now it is the turn of the support crew in the raft.

One, two, three.

Our worry is that the sharp rocks could damage the inflatable raft...

..so the boat has to be guided down.

The rock is impossibly spiky.

It is like daggers. And that could...

Well, it could pretty much rip the bottom out of our high-impact plastic boat.

The raft is, well, very, very vulnerable.

This is the first set of rapids and they're nothing in comparison to

what we think is going to be further down and it is already hard work.

With the raft over the worst of the sharp limestone...

-I'm ready.

-Three, two, one, go.

..we all head on.

-Nice, Steve.

-Gorgeous.

No kayaker has ever entered this impenetrable highland gorge before.

It is even possible we could be the first people ever to come here.

So all we need now is for the perfect campsite to open up for us.

Good luck, bro.

Finally we emerge from the steep-sided gorge.

Oh, chaps, I think we have got something.

Ahead, a small grassy island...

..in the middle of the Baliem.

You beauty!

All the faff aside, mate...

..it's a pleasure.

Well, we cut it pretty thin, but we have found paradise.

We have got the most extraordinary campsite here.

It is a raised, sandy island in the middle of the river.

That is going to be perfect to camp on.

While the river team prepare camp...

It is going to get cold, bro.

..I am off to find some of the life

that calls this high-altitude world home.

This place is a botanist's dream.

Everything has something else living off it, like this.

This is the ant plant.

You've got this bizarre kind of big bulb sat here on top of this rotting

tree, and this is a remarkable plant because it is also a home for ants.

It is the perfect example of symbiosis -

two organisms living side-by-side with mutual benefit.

The ants gain a house because inside here are little compartments where

they live, and the plant gets protection because anything that

tries to get stuck into it and eat it gets a mouthful of ants.

If I cut this open

then what you will see inside...

..is all of those chambers

where the ants live, and down the bottom there is where they have

their eggs and their larvae.

This one is only tiny, about the size of my fist,

but they get to be the size of basketballs.

Huge. And I'm getting eaten alive now.

Think I'll take the message.

You know, this is what I wanted to do when I was knee-high,

but I never thought it would actually happen.

And, you know, moments like this are unbelievably precious.

I've got some good tinder and kindling here.

The force of not knowing what is ahead and being the first people

to see something is a really powerful one.

I don't take it for granted for a second.

Morning.

I slept great.

Really well.

This grass is nice and soft and it's a lovely bed.

How are we doing?

Woke up about three, I think, for a couple of hours

and me and Barnes had a few little words to one another.

A little pillow talk.

Honestly, I've never felt so old in my entire life as I do on this trip.

All of a sudden surrounded by, like, 22-year-old rafters,

giggling away and talking in a language I don't even understand.

What's worse is that I've actually started picking all of it up

and all of a sudden I'm kind of going,

"Oh, yeah, that last rapid was sick,

"and I'm, like, totally stoked."

There is nothing more undignified than a 43-year-old man talking in

20-year-old surfer language.

It's day two.

Yesterday was a terrific start, but we did not get very far.

Today we are hoping to make up for lost ground,

kayak through the next gorge, and get within striking distance

of the Baliem Grand Valley.

I was just checking out my boat this morning,

which is brand-new, it has never been paddled before.

And look at all these gouges in the bottom of it.

So these are all from those really sharp limestone rocks.

This isn't going to make much difference to me.

I mean, you would have to be really going some to tear through

the bottom of one of these boats, but the problem is the raft -

it is just going to tear it apart.

And if we couldn't fix it then the expedition would effectively be over.

With the worry of the jagged rocks fresh in our minds...

Steve, in behind me, bro.

..we head off.

I can feel some good gouges in the bottom of my boat.

I've got some big ones in mine too.

It couldn't be much more calm though, beautiful.

It's incredible, it's just silent.

We paddle on, hoping to cover some good distance.

But then the river starts to narrow again.

Here we go. We're going back into it again.

You can hear the white water already.

As we are the first people to kayak this river, we just don't know

what lies ahead. It could be easy, it could be impossible.

What do you think? Should we get out to the left?

After only 2km, we come across a major obstacle.

Holy shit!

-This is going to be difficult with the raft.

-Yeah.

Basically none of this is runnable.

It is a big drop with churning white water...

..logjams and yet more jagged limestone boulders.

It could shred the raft and trap and drown any one of us.

Our first instinct is to portage, or carry, the kit over the obstacle.

Maybe the raft could handle one portage on this sort of stuff,

but if this is going to indicate what is downstream, it's something we need to consider very seriously.

We have two other options.

One is to carry on without the raft, leaving the crew behind,

meeting up with them further downstream.

The other is to pull out.

So we've got to think quite seriously about this.

Very seriously. This could be something else if we get

locked into a gorge, you know.

Jordy is concerned that, if we commit to the gorge,

we will be trapped or locked in.

No joke. It is very dangerous.

I for one definitely don't want to call for helicopter help.

Obviously to be thinking about leaving the river this soon

would be fairly crushing.

You know, we wanted to be doing a lot of white water before we had to take that option.

To add to our problems, two of the river crew,

David Bain and Nate Klema, are both feeling ill.

They are both suffering with severe headaches,

high temperatures and racing pulses.

Last night I got some pretty bad fever chills.

Definitely not 100%.

If it got much worse, I think I'd be struggling.

I've started coughing a little bit more and I'm feeling

a little bit hot, so I'm just concerned that, dropping

into the gorge in this state, if it did get worse, it might lead us into a little bit of trouble.

As lead kayaker, it is Jordy's decision whether or not to push on

with a depleted and debilitated team.

Kind of out of options, but just the exposure of Steve in there, you know.

If Steve loses the boat, if Steve gets injured...

When shit gets real, Steve may not be able to contribute as much

as someone like Nate or Adrian or David.

We can't really head downstream with just Steve, me and Barney.

Jordy thinks it is too risky,

so after only two days on the river,

he's called in the helicopter.

'I am absolutely furious.

'It feels like he is giving up way too easily.'

So I've just taken myself away just to have a little bit of a think.

It's a real shame.

I know that I'm kind of capable of taking on the stuff that is

downstream of here.

And that is...

..really, really frustrating.

I'm not loving life right now.

Once they have recovered, the river crew will seek out

the next place we can put back onto the river to continue our journey.

But for me, this expedition isn't just about the first descent

of the Baliem, it's also about exploring the extraordinary worlds

the river has created.

I am flying east over the highlands to a tributary of the Baliem

called the Wollo.

Because the rivers here are not just on the surface,

they also run underground.

I'm keen to get into that subterranean world to see how it

has been shaped by the waters of the Baliem Valley.

The mountains that form the central spine of New Guinea are composed of

limestone, which originally was created on the bed of a shallow sea.

But as the Pacific and Australian plates have come together,

they have squeezed the land up into these huge, towering mountains.

As the rock was pushed up over the past five million years,

so rivers carved out this stunning landscape.

But the water also started to seep through the rock and create

a whole new underground world,

almost all of which is totally unexplored.

And this is exactly what we're looking for.

It is a gigantic sinkhole or doline,

so originally that would have been a massive cave

and the roof's collapsed, leaving this enormous open hole.

Look at this cliff - that is insane!

It must be 250 metres high, completely vertical drop.

The caves we are hoping to explore are owned by several local villages.

THEY SPEAK LOCAL LANGUAGE

Our plan is to abseil down this precipice and to explore the caves

that we hope lead off it.

Because of the contours of the rock...

For that, I need a caving team.

..we're going to have to have a few belays in different positions.

Cave leader Steve Jones and his team of experts...

Do you want 10mm?

..are rigging hundreds of metres of rope for us to descend

into the cavern.

According to the locals, no-one has ever been down this way before.

We are abseiling into a 200 metre sinkhole

from the jungle, rigged off trees in the middle of Papua.

I don't think it gets any more epic than this.

While the caving team carry on,

I've found something that is just as exciting for me as a naturalist.

Somewhere in this small stand of trees in front of me

is a very special bird indeed.

It is a bird with a very big voice and every once in a while,

it is kind of letting rip, the male, with a sound that kind of goes...

HE IMITATES WHOOSHING

BIRD CALLS

That is the call. That is the call there.

There is one nearby. Let's go. Let's go this way.

It is the sound of the superb bird of paradise, and these

central highlands are the only place on Earth that you'll find them.

It is as unique to this part of the world as the Baliem is.

He is there, in the tree just ahead of us.

Absolutely magnificent.

It's the most incredible, glossy black colour,

except for that just ridiculous patch of blue over the breast.

He really is screaming to all the females around here to say,

"I am the biggest, most beautiful boy on the block."

He's gorgeous.

When I was a kid I had an encyclopaedia of birds of the world,

and the pages dedicated to the birds of paradise were pretty much

worn through from reading.

I was obsessed with them.

And, you know, they just seemed to be so impossibly glamorous,

from a place that was so exotic,

that I just never thought I would ever get a chance to go there,

to stand here and see one for real.

Our plan is to camp the night at the bottom of the sinkhole,

but then we get word that there is more trouble.

We have very real problems up top.

A person turned up and pretty much just said, "Get out of here."

'Jordy has been hauling kit from the nearby road,

'but this time instead of rope, he has brought bad news.'

We don't have the permissions.

Basically they are like, "You cannot stay here."

It turns out that not all the villages who claim ownership of

the caves are happy with our plans.

One of the real challenges of this part of the world and one of the

reasons why it's still so unexplored is that the people, you know,

they are distrustful of outsiders,

they have, you know, the deep pride in their land and the belief

that many parts of it are sacred,

and they have little or no value

of money so, you know, you can't necessarily bargain for things.

-Which is very frustrating.

-Let's get back up there now.

Our only option is to put the caving on hold

while we negotiate with the other village chiefs.

THEY SPEAK LOCAL LANGUAGE

The cave sits on the border of several villages

and while some of them are delighted to welcome us,

others are not.

I've been coming to this part of the world for 20 years,

so at least I can try and persuade them in their own language.

But it is not looking good.

What was "promise" again?

So...

..we're done, we're finished.

I just don't ever want to come to a place and leave bad feeling behind.

You know, I would be lying as well if I didn't say that I am devastated

not to be dropping down into that cave.

I stood on the lip and looked down into that cavern

and I could taste it.

After several days of searching, we finally find another cave.

This time the permissions are all in place.

-We have a hole.

-And big spider webs.

Just as well you're going first then, Steve.

We are hoping to push beyond the known portions of the cave

to find new passages and uncharted caverns.

It is good to be underground.

I am keen to find out how these caves are being formed,

to understand just how vast and extensive they are.

The constant temperature and protection from the elements

mean that the early sections of these caves

are a perfect hideaway for wildlife.

These shapes are swifts or swiftlets.

They hunt outside during the daylight and then come in here

to roost here at night.

But the most incredible thing is the sound they are making...

RAPID CLICKING

Like that, that little burst of clicks there.

So the swifts can't see in total darkness. Instead, what they are

doing is a kind of echolocating. They are making these sounds...

And it bounces back off the cave walls,

and they hear it and they can perceive in three dimensions.

They are flying blind but they can still find their way

into these caves where they are safe to roost,

as they are doing up above me.

Amazing.

Papua is one of the wettest parts of the world,

with an average 12 metres of rainfall a year up in the highlands,

compared to just one metre in the UK.

Over the past five billion years, as these mountains have been lifted up

out of the sea, so the endless rain has percolated

into the limestone bedrock.

That helps explain how these caves are forming.

Rainwater, which is very slightly acidic, seeps through thin cracks.

It slowly dissolves the rock,

eventually creating passages in caves like this one.

Wet mud underfoot suggests another process is also at work.

It shows that water often flows through these passages,

eroding them like a river erodes its channel.

Careful of this edge, cos that's a big drop-off,

and it seems to carry on going.

I'm going to scramble down and see what I can see.

We're over 3km into the cave system.

It has taken four hours to get this far.

-What was that?

-It's all right.

-Are we all good?

-Yes.

You have to be careful not to touch anything.

But it has been worth it.

Now that is impressive.

That is incredible.

In front of us is a vast cavern measuring over 100,000 cubic metres,

rather bigger than the Albert Hall.

There must be very, very little air movement

in this cave to allow all of this to form.

And it is big as well.

HE WHOOPS

Echo goes on forever.

That is a spectacular chamber.

You can see where the bedding planes in the cracks are,

the water's seeped through and that's where

all of those straws and stalactites form in lines.

Over the millennia, as mineral-laden water seeps through the limestone,

the steady drips create stalagmites...

..stalactites...

..and curtains cascading down the walls.

It's incredible that there are hidden places,

darkness that, you know, has never been illuminated before.

And that it can be so intensely beautiful.

Some of these formations are thousands,

if not millions of years old.

This truly is a lost world.

The thing that totally blows my mind

is that all those miles and miles of mountains that we've

flown over have all got this kind of thing below them, haven't they?

And there are so many infinite miles of caverns like this that have

definitely never been seen and possibly never will be seen.

Possibly never.

But I would put a big bet on Papua having more unexplored cave

than anywhere else in the world.

Water has created a whole new landscape inside these mountains.

And with the challenges we faced,

it is likely these subterranean wonders will remain hidden

for generations.

The river team are recovered and we're relaunching our Baliem descent

at the first available place downstream.

We're re-joining the river 10km as the crow flies

from where we left it, to start off the next phase of our journey

heading down to the Baliem Grand Valley.

Our plan is to kayak over 80km downstream,

through what we expect to be extreme white water,

until we reach the end of the Grand Valley.

Hold it there, Steve.

This is a land of small settlements and cultivation.

The main tribe are known as the Dani.

I'm hoping to find out more about them,

their relationship with the river,

and to see what impact the modern world is having

on their ancient way of life.

At the base of this gigantic cliff face we have here,

there are two tributaries coming together in a fork,

so that means there is a lot more water here and we're going to have

much less problems with sharp rocks tearing the bottoms

out of our boats.

So hopefully the paddling is about to begin, finally.

The river's increased flow means we're less likely to tear the raft,

but makes it faster and more dangerous.

Final checks done, we are off.

It looks epic from here, doesn't it?

It feels so good just to be on the water.

Although many of the Dani now wear modern clothes...

HE CALLS IN LOCAL LANGUAGE

..some of the older generation still use the traditional penis gourd,

with maybe a woollen beanie as the only concession to the 21st century.

People have been farming here in the Baliem Valley for a very long time.

Some suggest 32,000 years,

which would make it the longest consistent communities found

anywhere on Earth.

Much of this success is down to the rich alluvial soil.

Early visitors thought this valley was a Shangri-La,

a fertile place of plenty.

Evidence shows the Dani and many of the other 311 Papuan tribes

share genetic links to the aboriginals of Australia.

Come, come.

Until now, the river has been quite manageable

but we know it is bound to speed up.

Steve, it's starting to get a bit steeper now

and we want to catch that eddy where Barney is.

-See where Barney is downstream?

-Yes.

-Sweet.

Suddenly the river drops into a kilometre-long rapid.

It is bigger than anything I have tackled before.

Aldo is scouting ahead.

His massive problem here is that if he is not powerful enough coming

through here, he is going to get sucked into that hole.

If he ends up in that hole he's pretty much on his own.

Scary stuff.

This may sound funny, but you can paddle this rapid, OK?

-You can paddle it.

-Yep.

I need to prove to the team...

..and to myself, that I am up to it.

I only just miss hitting the rocks...

..but it is not over yet.

I'm getting sucked into the hole Aldo was worried about.

If I can't paddle my way out, I am in trouble.

Paddle! Paddle!

Paddle!

Yes! Yes!

-Yes!

-Yes! Yes!

Good boy.

That was amazing. That was amazing.

Tenacity is the key, bro.

-Tenacity.

-Oh, my God.

I've just got the biggest adrenaline hit ever.

It's going to be hard work making you swim on this trip, mate.

Wow.

Feeling like I can conquer anything, we paddle on.

Look at this.

Sensational!

Beautiful.

We meet more and more Dani along the river's edge,

many as keen to find out about us as we are about them.

It was only in 1938 that outsiders first visited the valley.

So they're saying that this man here is the kepala desa,

which is the head of the village,

and all my other new friends here are from a village

that is just up here.

HE SPEAKS THEIR LANGUAGE

It is close. Their village is very, very close to the river.

That is a sobering thing to hear.

The head of the village has just said that they had, just yesterday,

a woman fell into the river here and they have not found her body.

The river has a phenomenal amount of power and while it, you know,

brings life to these people, it gives them water for their agriculture,

to drink, to wash in, it can also take life away as well.

So we promised to look for the body downstream but, you know,

I doubt we will find it.

As we head on, the story of the lost woman still echoing in our minds...

..the river starts to build again

as we hit yet another rapid.

I'm sticking close to Jordy, with Barney providing safety cover

further downstream as usual.

But then, out of nowhere, my boat gets sucked into yet another hole.

The water is being churned into a swirling back-current

and it spins me around.

It is sucking me in, rolling me over and over.

And then...

YELLING

I'm out of my boat, on my own,

being swept downstream by the river in full flood.

Swim, bro, swim!

Barney throws me a safety line.

Which I just manage to grab.

And I haul myself back into the bank.

Steve, are you all right?

-I'm good.

-Wait there, Steve.

I will come to you. Wait there.

Luckily, Jordy saved my boat.

Could someone grab that?

And Barney saved me.

Thank you, mate.

It had to happen,

sooner or later.

I got sucked into a hole...

..and flipped, I don't know, maybe five or six times.

It was scary. I mean, I knew the second I went into that hole,

I knew that I was history, really.

I kind of hit it wrong and it sucked me back in and, yeah,

it was time to pull the ripcord.

We paddle on.

Playing it safe...

..taking it steady...

..as the river slows down and the valley broadens out.

We're coming towards the end of a long day, at least 40km,

possibly even 50, and we're losing light and it's starting to rain,

so it's time for us to try and find camp.

There is a small settlement here, just a few huts

up beyond the river bank.

And the youngsters certainly seem friendly.

We have lucked out. These Dani villagers seem more than happy

to let us stay the night.

It is also a wonderful opportunity to find out more

about these remarkable people.

This is great.

So we have... There is one more modern building to the side here,

which has an aluminium roof,

but the rest of them are all old-fashioned, beehive-style huts.

They are called honai, and are the traditional Dani homes

with thatched roofs and wooden walls.

THEY SPEAK LOCAL LANGUAGE

All the generations live in this compound together,

including the 70-year-old village elder.

40-year-old chief Eli Mabel and his brother Martin

are the 11th generation to live in this small settlement of Pumo.

Outside, the extended family are cooking dinner.

It is traditional for group meals or special occasions to be cooked

in a big fire pit with hot stones to slow-bake the food.

Eli's mother is in charge.

OK, OK.

But it is a different tradition that has grabbed my attention.

This is something that is practised by the Dani women.

When they lose someone, when they are in mourning,

they will cut off their own fingers as a sign of grief.

Sometimes the only kind of anaesthetic they will have

before these digits are removed is that someone will punch them

really hard in the arm, and give them a dead arm and then, bam,

off it comes with an axe, believe it or not.

It sits quite uncomfortably, I guess,

with our whole Western idea of equality between the sexes,

but you see so much of that here in Papuan culture,

the women really do all the work,

all the hard work and a lot of time the guys just kind of sit around

smoking and laughing.

The Dani men also spend a lot of time chewing a mild narcotic

called betel nut.

All of it? He's saying, take all of it.

The whole nut?

-Yeah, the inside.

-It is the fruit of the areca palm

that is found in much of the tropics and Aldo is keen to give it a go.

Do you swallow?

No, no, no, never swallow.

Make that a rule for life.

It tastes really, really bitter.

And you say not to swallow, but my mouth is full and dribbling.

The betel makes Aldo dribble, turns his spit blood-red in colour,

and makes him sweat.

Yeah, come on, Barney. It can also make you feel a little tipsy.

I'm very hot.

It's remarkable. It's almost instantaneous, you're sweating.

And you've now got bright red lipstick on as well.

And your massive sweaty face!

The Dani have a communal spirit we are sadly losing.

It is all about sharing and spending as much time together as possible.

And there is no sense of privacy.

In fact, the word in this language

for being solo is the same as the word for being lonely.

People should want to be together,

that is very much a part of the culture here.

There is a great respect for the elders,

and that extends beyond the grave.

Come and have a little look.

In the men's honai, village chief Eli shows me a family heirloom.

Oh, that is extraordinary.

It was commonplace for the Dani to keep a respected ancestor

as a mummy, but as a practice, it is now in decline.

The mummy's kept in the men's hut and it is considered an honour

to sleep in the same space as him.

He was killed in a battle with a nearby village and having him

made into a mummy is a kind of way of honouring him.

After he died, his body was cleaned and prepared and he was then smoked

over the fire in the men's hut for six months.

He provides a powerful physical connection to their past.

It is now two o'clock in the morning

and the guys have finally stopped talking.

It's kind of weird looking around and seeing behind me...

..the one guy who kind of seems to be sat up in a weird position.

I know it is a great honour and a privilege to sleep here

in the men's house alongside this ancient mummy,

and they have told me that this will bring me prosperity,

and a blessing for the rest of my life and I will be able to have

lots and lots of wives.

I'm not sure what Helen will think of that.

It gives me great joy to find communities like this

where the Dani's vibrant culture is still treasured.

This is one of the world's most ancient cultures.

It is a rare case of tradition surviving in a fast-changing world.

Young and old still value their heritage, what it means to be Dani.

We were welcomed here like long lost friends and returned to the river

full of optimism and hope for the rest of our journey.

Next time...

This is the first settlement we've actually seen marked on a map

for about 10 days.

When it is in full flood, it has the power to move along boulders

that are the size of cars.

Paddle, paddle, paddle!