0:00:02 > 0:00:05Look at this place! Simply breathtaking.
0:00:08 > 0:00:12Welcome to New Guinea, the world's largest jungle island.
0:00:12 > 0:00:16One of the most remote and unexplored parts of our world.
0:00:17 > 0:00:22It's very intimidating, potentially very dangerous.
0:00:22 > 0:00:26But also one of the most exciting places on the planet.
0:00:26 > 0:00:30Running from its mountainous heart, over 500km,
0:00:30 > 0:00:32through pristine wilderness,
0:00:32 > 0:00:35wild gorges and tropical jungle out to the sea...
0:00:38 > 0:00:39..is the mighty Baliem River.
0:00:42 > 0:00:45I was expecting it to be big...
0:00:46 > 0:00:48..but I wasn't expecting that.
0:00:49 > 0:00:54No-one's ever travelled the full length of this untamed river before.
0:00:54 > 0:00:59We've managed to turn a simple side trip into an absolute epic.
0:01:00 > 0:01:04I'm Steve Backshall. I'm a naturalist and an adventurer.
0:01:04 > 0:01:07It just looks like there should be dinosaurs everywhere.
0:01:07 > 0:01:11I want to explore the river and discover more about the remarkable
0:01:11 > 0:01:14variety of worlds through which it travels.
0:01:14 > 0:01:15Ow! Shoot!
0:01:17 > 0:01:19It's home to ancient tribes.
0:01:21 > 0:01:25'I want to see how they're coping with the modern world.'
0:01:25 > 0:01:26When they're in mourning,
0:01:26 > 0:01:29they will cut off their own fingers as a sign of grief.
0:01:29 > 0:01:32'I'll be searching for some of the world's scariest animals.'
0:01:32 > 0:01:35It was basically eating its way through the village.
0:01:35 > 0:01:39'And exploring a vast, uncharted, underground world.'
0:01:39 > 0:01:42Now, that is impressive!
0:01:42 > 0:01:44'But the Baliem is so inaccessible,
0:01:44 > 0:01:48'the only way to uncover its secrets is to travel its length from source
0:01:48 > 0:01:49'to sea...'
0:01:49 > 0:01:52We are committed now.
0:01:52 > 0:01:53'..by any means possible.
0:01:56 > 0:01:59'It could give us a unique insight into one of the last truly
0:01:59 > 0:02:03'wild places on earth.' Where the hell are you taking us, Aldo?
0:02:03 > 0:02:07- Oh, mate.- 'Or it could be a journey too far.'
0:02:09 > 0:02:10Jordy!
0:02:23 > 0:02:26'We are halfway through our five- week expedition into the heart
0:02:26 > 0:02:28'of New Guinea.'
0:02:28 > 0:02:31This bit's really slippy.
0:02:31 > 0:02:32'Expedition safety expert
0:02:32 > 0:02:36'Aldo Kane and I are scouting out the next section of our journey.
0:02:36 > 0:02:40'The toughest and most dangerous part of our trip...
0:02:40 > 0:02:41'the dreaded Lower Gorge.'
0:02:44 > 0:02:46This is very much the crux of the expedition.
0:02:46 > 0:02:50If we're going to be able to travel the Baliem from source to sea,
0:02:50 > 0:02:52this is the breaking point.
0:02:58 > 0:03:01'Our expedition has brought us to Papua,
0:03:01 > 0:03:05'a province of Indonesia that makes up the western half of New Guinea.
0:03:07 > 0:03:11'Our plan is to travel by boat from here to the sea.'
0:03:12 > 0:03:14The river drops down...
0:03:15 > 0:03:20..a vertical mile in the space of less than 100km.
0:03:20 > 0:03:22Oh, crap.
0:03:22 > 0:03:23That gives me the willies.
0:03:27 > 0:03:30'This was supposed to be the dry season, but we've had
0:03:30 > 0:03:34'unseasonal rains and we're worried the river will be in full flood.'
0:03:36 > 0:03:40This part, the gorge, just fills me with terror.
0:03:43 > 0:03:46'Our aim is to kayak the Baliem's Lower Gorge -
0:03:46 > 0:03:49'80km of death-defying white water.'
0:03:49 > 0:03:53Crashing down through impenetrable rainforest before it reaches
0:03:53 > 0:03:55South Gap, the end of the Gorge.
0:03:55 > 0:03:59From here, the river winds 200km through lowland jungle into the land
0:03:59 > 0:04:03of the Asmat, a tribe famous for their recent history of headhunting
0:04:03 > 0:04:05and cannibalism.
0:04:05 > 0:04:08Finally, our expedition will end at the Pacific Ocean.
0:04:14 > 0:04:17'We are hoping to meet remote and potentially hostile tribes
0:04:17 > 0:04:19'and to see some of the extraordinary wildlife
0:04:19 > 0:04:23'that lives along the banks of the isolated Lower Gorge.'
0:04:28 > 0:04:31I was expecting it to be big...
0:04:32 > 0:04:34..but I wasn't expecting that.
0:04:35 > 0:04:37That's impossible.
0:04:38 > 0:04:41Once you get further down into that gorge, for the next however,
0:04:41 > 0:04:4580-odd kilometres that it is, there's no way of getting out.
0:04:45 > 0:04:48You can see behind us where the gorge actually starts.
0:04:48 > 0:04:51And the rock walls come in, they get tighter and tighter,
0:04:51 > 0:04:56the river constricts and all of that volume of water is intensified.
0:04:56 > 0:05:00And so it is flowing at a steeper gradient with an increased volume
0:05:00 > 0:05:05and it is going to be even more challenging than this.
0:05:08 > 0:05:12If you paddle into that, you would definitely die.
0:05:12 > 0:05:14'It's clear we can't begin here.
0:05:15 > 0:05:19'We'll have to hop over this section and begin deep inside the Gorge.
0:05:22 > 0:05:25'Which means resorting to a helicopter.
0:05:28 > 0:05:31'It's a compromise to the pure expedition I wanted,
0:05:31 > 0:05:34'but with hundreds of kilometres of river left,
0:05:34 > 0:05:37'there's still plenty of exploration ahead.'
0:05:40 > 0:05:44Going down through here seems somewhere so extraordinary,
0:05:44 > 0:05:48so beautiful and thinking we can be the first people ever
0:05:48 > 0:05:51to come down here is mind-blowing.
0:05:54 > 0:05:57'We are scanning the banks for a place we can land
0:05:57 > 0:05:59'and finally start kayaking.'
0:06:02 > 0:06:04This section of the gorge we were going into before,
0:06:04 > 0:06:06no-one's ever attempted it.
0:06:06 > 0:06:09There is no decent map.
0:06:09 > 0:06:13'The river is one of the wildest, most potentially lethal on earth.
0:06:13 > 0:06:17'But we've got a world-class kayaking team led by New Zealander,
0:06:17 > 0:06:18'Jordy Searle.'
0:06:18 > 0:06:23Down here, I would say it's by far the most isolated I've ever been.
0:06:27 > 0:06:31'10km downstream, we finally find what we are looking for.'
0:06:31 > 0:06:35So from here on in, the water is epic, it's massive.
0:06:36 > 0:06:38But it looks doable.
0:06:41 > 0:06:44'Our team is four kayakers and a camera crew,
0:06:44 > 0:06:47'plus hundreds of kilos of camping and filming gear packed into two
0:06:47 > 0:06:48'inflatable rafts.
0:06:52 > 0:06:54'And now, we're on our own.'
0:07:04 > 0:07:06Row with nice big, positive strokes.
0:07:13 > 0:07:15'Our first paddle strokes on the Lower Gorge.
0:07:19 > 0:07:21'It's as exciting as it is daunting.'
0:07:25 > 0:07:29This river has so many different changing faces,
0:07:29 > 0:07:33even here in the gorge, it's changed completely.
0:07:33 > 0:07:36Now we're heading down into this fantastic gully.
0:07:41 > 0:07:44There are creepers and vines covering all the trees.
0:07:44 > 0:07:47It just looks like there should be dinosaurs everywhere.
0:07:47 > 0:07:50But instead of pterodactyls flying overhead,
0:07:50 > 0:07:52we have hornbills and parakeets.
0:07:53 > 0:07:56This is one of the most extraordinary places I've ever seen.
0:08:01 > 0:08:05'The rampaging river makes much of the gorge completely inaccessible.
0:08:05 > 0:08:08'The surrounding forests are doubtless filled with
0:08:08 > 0:08:10'unknown animals and remote tribes.
0:08:12 > 0:08:15'It's incredible to think we are the first outsiders ever to kayak here.
0:08:16 > 0:08:18'Maybe even to see this place.
0:08:22 > 0:08:24'But as we head around the next corner,
0:08:24 > 0:08:25'the river changes character.'
0:08:28 > 0:08:29This looks massive.
0:08:34 > 0:08:37'Ahead - the biggest rapid we've yet faced on the Baliem.
0:08:40 > 0:08:43'As the river carves its way down the canyon,
0:08:43 > 0:08:45'it hits a wall of limestone,
0:08:45 > 0:08:47'forcing it to turn right.
0:08:50 > 0:08:53'Getting trapped in that would be very bad indeed.'
0:08:58 > 0:09:00So this is it.
0:09:00 > 0:09:02This is bigger than anything I thought I'd be taking on
0:09:02 > 0:09:03on this river.
0:09:03 > 0:09:06And if I pick the right line, it'll be great.
0:09:06 > 0:09:08If I mess it up, it's going to be horrific.
0:09:12 > 0:09:14I've got this zing of adrenaline, I'm just...
0:09:16 > 0:09:19..shaking, my hands are kind of...
0:09:19 > 0:09:20going.
0:09:27 > 0:09:30Barney, Steve, me.
0:09:30 > 0:09:33'Kayaker Barney Young is going first to pick the route.
0:09:34 > 0:09:36'Jordy and I will follow.'
0:09:36 > 0:09:37On his tail, Steve.
0:09:40 > 0:09:43'Barney's paddling straight into the middle of the river, trying to keep
0:09:43 > 0:09:45'the small gravel island on his left...
0:09:47 > 0:09:50'..to give him a fighting chance of keeping clear of smashing
0:09:50 > 0:09:51'into that wall.
0:09:54 > 0:09:57'He makes it, but I've been caught out and I'm heading
0:09:57 > 0:10:00'completely off course.'
0:10:00 > 0:10:01Dammit!
0:10:01 > 0:10:03'Jordy steps in.'
0:10:06 > 0:10:07Big line.
0:10:07 > 0:10:09- Right.- Watch your speed.
0:10:09 > 0:10:10Yeah.
0:10:12 > 0:10:15We power back into the main current, paddling frantically,
0:10:15 > 0:10:17'trying to avoid the horror of the wall.
0:10:22 > 0:10:26'But the colossal volume of water hurtles me towards the rock,
0:10:26 > 0:10:29'threatening to crush me, then suck me down into the whirlpool.'
0:10:32 > 0:10:33HE SCREAMS
0:10:37 > 0:10:39Paddle, paddle, paddle!
0:10:39 > 0:10:40'The wave hits me side-on.
0:10:48 > 0:10:49'I'm capsized.
0:10:51 > 0:10:52'Battling to roll back up.'
0:10:52 > 0:10:55Paddle, paddle, paddle!
0:10:56 > 0:10:57Yes!
0:11:00 > 0:11:02Paddle. All the way to Barney.
0:11:03 > 0:11:06'There's no let-up.
0:11:06 > 0:11:09'I still have to get across the river to Barney.'
0:11:09 > 0:11:12Steve, paddle. Lean forward and paddle.
0:11:14 > 0:11:17'If I don't make it, I could end up being swept downstream into the next
0:11:17 > 0:11:18'set of rapids.'
0:11:20 > 0:11:22Aghh!
0:11:22 > 0:11:23Holy crap!
0:11:25 > 0:11:27Aghh!
0:11:27 > 0:11:29Oh, my God.
0:11:29 > 0:11:32- Oh, my God. - Bro, I'm not going to lie,
0:11:32 > 0:11:34I thought you were going to swim in there, man.
0:11:34 > 0:11:37I'm going to remember that for the rest of my life.
0:11:37 > 0:11:41I've just taken the biggest hit of adrenaline.
0:11:42 > 0:11:46My entire body is shaking.
0:11:51 > 0:11:53There was a moment there where I hit that wave,
0:11:53 > 0:11:56bouncing back off the wall and it flipped me instantly.
0:11:56 > 0:12:00I was under water thinking, "Do not come out of your boat here."
0:12:02 > 0:12:05To be pinned against that wall with all this water,
0:12:05 > 0:12:07you wouldn't stand a chance.
0:12:09 > 0:12:11'It was a close call.
0:12:11 > 0:12:14'Now it's the turn of the rafts carrying the camera team
0:12:14 > 0:12:16'and all our gear to brave the rapids.
0:12:19 > 0:12:23'They need to follow our route and keep well away from the wall.
0:12:25 > 0:12:27'Flipping here would be disastrous.
0:12:32 > 0:12:34'The first raft just misses the wall.
0:12:40 > 0:12:43'But the second one hits it head-on...
0:12:49 > 0:12:52'..before flushing them clear, battered and shaking.'
0:13:05 > 0:13:07'The rapids are endless.
0:13:12 > 0:13:15'An island midstream is a chance to regroup.'
0:13:20 > 0:13:23This actually isn't supposed to be an island,
0:13:23 > 0:13:25we are supposed to be joined up with the river bank here,
0:13:25 > 0:13:30but because the flow is so high, there's a river flowing both sides of it.
0:13:30 > 0:13:33There's a stump that should be on dry land
0:13:33 > 0:13:36and is completely overwhelmed.
0:13:38 > 0:13:42'Barney's pushing ahead to scout the next bend
0:13:42 > 0:13:45'and what lies beyond it.'
0:13:45 > 0:13:50So far, we've managed to handle everything the river has thrown at us.
0:13:50 > 0:13:53But you just never know what's around the next corner.
0:13:53 > 0:13:56'And his radio report brings bad news.'
0:13:58 > 0:14:02- WALKIE TALKIE:- All pumping to the centre and then it just looks
0:14:02 > 0:14:06like it drops off the face of this earth.
0:14:06 > 0:14:10'Up ahead is the wildest white water any of us have ever seen.'
0:14:12 > 0:14:14That's horrific.
0:14:14 > 0:14:18This river is just not going to give it up easy.
0:14:20 > 0:14:23Totally un-paddleable, not a chance of getting down that.
0:14:25 > 0:14:29The river just drops into a huge maelstrom of like big holes,
0:14:29 > 0:14:33big crashing waves, dwarfing anything we've seen so far.
0:14:33 > 0:14:38And if one small mistake is made in here, there's no way to recover,
0:14:38 > 0:14:40you're going straight into that next section.
0:14:46 > 0:14:49'Once again, we've hit a section that we can't kayak.
0:14:49 > 0:14:50'We are trapped.
0:14:54 > 0:14:57'But flood levels like this do at least give an insight into the
0:14:57 > 0:14:58'river's destructive power.'
0:15:01 > 0:15:04It could just take away these mountainsides.
0:15:04 > 0:15:08And that of course is what's created the Baliem Gorge.
0:15:10 > 0:15:14'The sheer force of the water tumbles rocks downstream,
0:15:14 > 0:15:18'grinding away at the bedrock, scouring out the river camp.
0:15:18 > 0:15:20'It's erosion at its most powerful.'
0:15:22 > 0:15:24When it's in full flood,
0:15:24 > 0:15:29it has the power to move along boulders that are the size of cars.
0:15:29 > 0:15:32'It's a mighty, yet sobering spectacle.
0:15:35 > 0:15:37'Dusk is starting to fall.
0:15:37 > 0:15:40'We are exhausted, beaten and bruised.
0:15:40 > 0:15:44'Decisions on what to do next will have to wait until tomorrow.'
0:15:59 > 0:16:02'At night, the jungle comes alive.'
0:16:09 > 0:16:12The animal life here in New Guinea
0:16:12 > 0:16:15is very much Australasian.
0:16:16 > 0:16:18Until the last ice age,
0:16:18 > 0:16:21New Guinea and Australia would have been linked up and there would have
0:16:21 > 0:16:24been land bridges allowing animals to move freely.
0:16:24 > 0:16:27'That was over 10,000 years ago,
0:16:27 > 0:16:31'but the forests of Papua are still home to marsupials,
0:16:31 > 0:16:32'wallabies and kangaroos.
0:16:32 > 0:16:35'Though here, they live up in the trees.
0:16:35 > 0:16:38'There are also giant, flightless cassowaries
0:16:38 > 0:16:40'and of course, reptiles.'
0:16:40 > 0:16:43It is an absolute little beauty.
0:16:43 > 0:16:46It's a water dragon.
0:16:46 > 0:16:49They are a kind of agamid lizard.
0:16:49 > 0:16:51In some kinds of lizards like this, the tail can be used as a weapon,
0:16:51 > 0:16:56lashed from side to side and these spines could be used as a sort of
0:16:56 > 0:16:58lacerating protective tool.
0:16:58 > 0:17:01Despite the fact he has a fairly menacing appearance,
0:17:01 > 0:17:04he is totally and utterly harmless to us.
0:17:04 > 0:17:07They can move surprisingly fast over the land. Living this close
0:17:07 > 0:17:10to the water gives them a great defence against predators.
0:17:10 > 0:17:14Anything that comes up, they can just leap into the water.
0:17:14 > 0:17:20When they swim, these legs come back to lie along the base of the tail
0:17:20 > 0:17:24like that and the tail is whipped side to side using the musculature
0:17:24 > 0:17:27here to give them propulsion.
0:17:27 > 0:17:31So these particular lizards are found all the way through New Guinea
0:17:31 > 0:17:33and down into the north of Australia.
0:17:33 > 0:17:38And they are conclusive proof of the fact that the two land masses were,
0:17:38 > 0:17:41as recently as the last ice age, joined together.
0:17:41 > 0:17:44He is absolutely fantastic.
0:17:44 > 0:17:48And the tail goes on forever.
0:17:48 > 0:17:49Look at that!
0:17:51 > 0:17:55So I have just aimed him away from camp and I'm sure he'll scamper off.
0:18:05 > 0:18:08THUNDER ROLLS AND RAINDROPS PATTER
0:18:16 > 0:18:20It has been raining for six solid hours, quite heavily.
0:18:20 > 0:18:23The river's come up by another metre.
0:18:24 > 0:18:28- Maybe more.- And not only can't we continue downstream,
0:18:28 > 0:18:31we can't get out of here either.
0:18:31 > 0:18:38What was solid, some of the craziest white water in the world...
0:18:39 > 0:18:41..has got bigger and crazier.
0:18:42 > 0:18:43So we are stuck.
0:18:46 > 0:18:49'The bad weather means we can't call for a helicopter,
0:18:49 > 0:18:52'so for the next day at least, we are trapped here.
0:19:01 > 0:19:04'But it does mean I get a chance to have a proper look around.'
0:19:12 > 0:19:16I have to say, this is one of the prettiest patches of forest
0:19:16 > 0:19:18I've ever spent any time in.
0:19:19 > 0:19:22All these splashes of colour, these blooms like this,
0:19:22 > 0:19:27seem even more fragile when they are alongside that massive,
0:19:27 > 0:19:28torrential river.
0:19:32 > 0:19:35'Orchids like these thrive at the riverside.'
0:19:35 > 0:19:40You get these incredible displays of colour and that, very much,
0:19:40 > 0:19:42is designed to attract the pollinators.
0:19:44 > 0:19:47Just in here is a paper nest,
0:19:47 > 0:19:51which has been made from chewed-up tree bark and wasp spit,
0:19:51 > 0:19:56essentially. And gathered around it are a whole host of wasps.
0:19:56 > 0:20:00So a fair few times, working in forests like these,
0:20:00 > 0:20:04I've brushed into nests like this and got stung a couple of times
0:20:04 > 0:20:06and then just kind of swatted the wasps.
0:20:06 > 0:20:10And when you do that, they release a pheromone which smells
0:20:10 > 0:20:12like ripe bananas. And it's an attack pheromone -
0:20:12 > 0:20:15it convinces all the others to start stinging too.
0:20:15 > 0:20:18You end up charging for the nearest body of water with your arms
0:20:18 > 0:20:20flailing around all over.
0:20:21 > 0:20:22Ow! Shoot!
0:20:26 > 0:20:30I just seriously went against
0:20:30 > 0:20:33working with wasps and bees
0:20:33 > 0:20:35rule one!
0:20:37 > 0:20:41I must spend so much of my life telling people,
0:20:41 > 0:20:43"If you are near wasps and bees, don't swing your arms around
0:20:43 > 0:20:47"all over the place because it agitates them."
0:20:47 > 0:20:50And that's really spicy.
0:20:50 > 0:20:51Ow!
0:20:52 > 0:20:54HE LAUGHS
0:21:00 > 0:21:02'With no sign of the weather improving,
0:21:02 > 0:21:05'Aldo and I decide to make the most of it and try and find one
0:21:05 > 0:21:08'of the elusive tribes that live out here.'
0:21:12 > 0:21:15Ah! 'And the signs are promising.'
0:21:15 > 0:21:16Look at this.
0:21:18 > 0:21:26It's a hunter's hut and I can still smell that damp ember smell,
0:21:26 > 0:21:29which means this fire is relatively recent.
0:21:31 > 0:21:35'The dominant tribe in this part of Papua are the Yali.
0:21:35 > 0:21:37'Their villages abound in the wild lands
0:21:37 > 0:21:40'that surround the Baliem Gorge.
0:21:40 > 0:21:43'If we can find one of their villages, it would be a real coup.'
0:21:46 > 0:21:50So if we look around here, there's bound to be a trail that heads up
0:21:50 > 0:21:53there and I bet anything there's a village somewhere
0:21:53 > 0:21:55on the hillsides above us.
0:21:58 > 0:22:00'With their own distinct language and culture,
0:22:00 > 0:22:04'many of the Yali live their lives shut away from the outside world.
0:22:06 > 0:22:10'Finding a trail to their village is easier said than done.'
0:22:15 > 0:22:17- Is that yes?- Yeah.
0:22:18 > 0:22:21Certainly not as well used as the stuff we've just come through.
0:22:21 > 0:22:26It's maybe not used that frequently, but it's definitely a walkway.
0:22:29 > 0:22:31I'm not convinced, if I'm honest, mate.
0:22:32 > 0:22:33No.
0:22:36 > 0:22:38T-shirt or something there.
0:22:39 > 0:22:40Rag.
0:22:46 > 0:22:47Well, this is the path.
0:22:49 > 0:22:53I'd imagine we'd zigzag up onto this ridgeline here.
0:22:54 > 0:22:57'This old hunter's trail is overgrown and little used.
0:22:58 > 0:23:02'It's a struggle to cover any distance and painfully slow.'
0:23:04 > 0:23:06Thick, isn't it?
0:23:10 > 0:23:11Cheers.
0:23:16 > 0:23:19'The occasional chopped-down tree is another trail marker.'
0:23:21 > 0:23:24That's been covered. 'Signs the Yali have been here.
0:23:29 > 0:23:32'The terrain gets steeper and steeper.
0:23:32 > 0:23:35'It's humid, sweaty and slippery.
0:23:37 > 0:23:39'Even the wildlife seems to be taunting us.'
0:23:44 > 0:23:50I just walked into the mother of all spider's webs.
0:23:50 > 0:23:52And this is the culprit.
0:23:54 > 0:23:55She is Nephila.
0:23:57 > 0:23:59A golden silk orb-web-weaving spider.
0:24:01 > 0:24:05She is a reasonable size, but they can get to be enormous.
0:24:05 > 0:24:10This incredible spider, although I guess it looks extremely creepy,
0:24:10 > 0:24:13is harmless to us as human beings.
0:24:13 > 0:24:17'The webs are strung across the open paths to target flying insects,
0:24:17 > 0:24:21'but have been known to catch small birds and even bats.
0:24:21 > 0:24:24'She'll inject them with enzymes that liquefy their insides
0:24:24 > 0:24:26'and then suck out the meat soup.'
0:24:26 > 0:24:29Right, I'm going to put her back on this leaf here.
0:24:30 > 0:24:34See that long thread of golden silk.
0:24:34 > 0:24:38For its size and its diameter, it's stronger than steel.
0:24:40 > 0:24:43'As I'm out front, I'm the one walking into all the webs.'
0:24:45 > 0:24:48And I am trussed up in it properly.
0:24:49 > 0:24:50It's all in my hair.
0:24:51 > 0:24:53Ugh. Grim.
0:25:06 > 0:25:10'After hours of struggling uphill, we break out of the trees.
0:25:10 > 0:25:12'But it's not the Yali village we were hoping for.'
0:25:15 > 0:25:16Now that is a view!
0:25:18 > 0:25:20- Wow!- Stunning.
0:25:21 > 0:25:25It's not often in the rainforest you pop out and get a view like that.
0:25:25 > 0:25:29Usually you are just completely encased in this dark green cavern
0:25:29 > 0:25:32and all of a sudden, seeing this.
0:25:32 > 0:25:35'It's amazing to think this was once a seabed.
0:25:35 > 0:25:38'Marine fossils in the rock prove it.
0:25:38 > 0:25:39'Over the last 5 million years,
0:25:39 > 0:25:43'these layers of ocean floor were lifted up to form mountains.
0:25:43 > 0:25:47'Then rivers like the Baliem got to work, carving out deep valleys.'
0:25:48 > 0:25:50Being here
0:25:50 > 0:25:55gives you a real sense of quite what it is we've taken on here, you know.
0:25:55 > 0:26:00The river is an absolute beast, but the second you come away from it,
0:26:00 > 0:26:01the forest is even harder.
0:26:03 > 0:26:04We've taken...
0:26:05 > 0:26:10..three and a half hours to get here and we are...
0:26:12 > 0:26:14..about a kilometre away from where we started.
0:26:14 > 0:26:16Only 200 metres in height.
0:26:16 > 0:26:18Only 200 metres in height.
0:26:18 > 0:26:19Massive mosquitoes.
0:26:19 > 0:26:21Massive, massive mosquitoes.
0:26:23 > 0:26:28It's 4.30 now, so it's going to be dark in just over an hour or so.
0:26:28 > 0:26:31I don't think we're going to get to that village, do you?
0:26:31 > 0:26:33No, there's no way.
0:26:33 > 0:26:36'We may have utterly failed to find the elusive Yali village on the
0:26:36 > 0:26:39'ridgeline, but it's given us a different perspective on the river
0:26:39 > 0:26:41'and the landscape that it's shaped.'
0:26:42 > 0:26:44There's no water up here.
0:26:44 > 0:26:46We can't really camp up here comfortably,
0:26:46 > 0:26:50so we are going to have to head down and fast otherwise we will be
0:26:50 > 0:26:55sliding down the slopes in the dark, and that would be very unwise.
0:26:55 > 0:26:57I think we'll end up in the dark anyway.
0:27:00 > 0:27:04'Sure enough, as soon as we drop back under the dense canopy,
0:27:04 > 0:27:05'the light fades.'
0:27:13 > 0:27:17The jungle is so difficult to navigate in daylight...
0:27:18 > 0:27:19..never mind night-time.
0:27:21 > 0:27:23Keep your wits about you.
0:27:25 > 0:27:29'The trail was tricky to find before. Now, in the dark,
0:27:29 > 0:27:30'we quickly lose our bearings.'
0:27:33 > 0:27:35First thing you learn about being in the jungle
0:27:35 > 0:27:37is don't fight the forest.
0:27:38 > 0:27:42Move as slowly, carefully and easily as you can...
0:27:43 > 0:27:46..because otherwise you are going to come a cropper.
0:27:50 > 0:27:53'The only way on is to head down towards the roar of the river.'
0:27:57 > 0:27:59Right, nice and gently, guys, really gently.
0:28:00 > 0:28:02If you fall, shout.
0:28:02 > 0:28:04Keep your legs together.
0:28:07 > 0:28:09Everyone just be super careful.
0:28:09 > 0:28:13That's a big drop so maybe push round to the left.
0:28:15 > 0:28:16We are in a nightmare scenario now.
0:28:16 > 0:28:18Can't see the track.
0:28:18 > 0:28:20Nothing really to hold on to.
0:28:23 > 0:28:24Careful, mate. Careful.
0:28:25 > 0:28:29- Where the hell are you taking us, Aldo?- Oh, mate.
0:28:29 > 0:28:34We've managed to turn a simple side trip into an absolute epic.
0:28:37 > 0:28:39Everyone's exhausted.
0:28:39 > 0:28:42We've been going for much too long.
0:28:46 > 0:28:49Be super careful. I can't see how steep it is here.
0:28:52 > 0:28:55The river's getting louder as we get closer.
0:28:55 > 0:28:59'But we've no idea if we're about to walk into our camp or the rapids.'
0:29:01 > 0:29:02I can see the water now.
0:29:04 > 0:29:05Thank God for that.
0:29:05 > 0:29:07Yeah, sorry.
0:29:07 > 0:29:10It's always an epic moving at night in the jungle.
0:29:13 > 0:29:15'It's been a huge, physically draining day.'
0:29:22 > 0:29:24Oh, I am beat.
0:29:36 > 0:29:39At first light, the cloud cover is still hanging over the valley.
0:29:42 > 0:29:45The chance of a helicopter rescue is looking unlikely.
0:29:46 > 0:29:48The weather doesn't look particularly good for it,
0:29:48 > 0:29:53but everything kind of hinges on us getting out of here this morning.
0:29:53 > 0:29:56'Low cloud and rain is not on our side.
0:30:01 > 0:30:04'But then we get word - the chopper is on its way.
0:30:15 > 0:30:18'The daredevil pilot has ducked in beneath the clouds.
0:30:18 > 0:30:21'We only have only minutes to tear down camp and load the gear
0:30:21 > 0:30:23'in case the clouds close in again.'
0:30:26 > 0:30:30Cannot believe I'm back in a helicopter again.
0:30:34 > 0:30:37'Our aim is to make a short hop over this impassable section.
0:30:43 > 0:30:46'But below us, the river has risen again.
0:30:52 > 0:30:55'Every minute we are in the air, we're flying over more of the river
0:30:55 > 0:30:57'we'd like to paddle and explore.
0:30:57 > 0:31:00'We scan the gorge, desperate for water we can actually paddle.
0:31:05 > 0:31:09'Nearly 15km pass below us before we find a place the heli can set down.
0:31:13 > 0:31:15'The river is still a raging torrent,
0:31:15 > 0:31:18'but the hope is that we can paddle from here to the end of the gorge
0:31:18 > 0:31:19'at South Gap.
0:31:24 > 0:31:25'We are just very, very lucky'
0:31:25 > 0:31:27the helicopter can come to our aid
0:31:27 > 0:31:30and bring us down here, cos where we are now, we can start again.
0:31:32 > 0:31:35There is still a lot of river left, a lot of river,
0:31:35 > 0:31:38like probably 300km of river left.
0:31:45 > 0:31:47From its source in the mountains,
0:31:47 > 0:31:51the Baliem has already dropped two vertical miles in height.
0:31:51 > 0:31:54Massively swollen from the extra rain...
0:31:55 > 0:31:57..this is the Baliem at its mightiest.
0:32:02 > 0:32:07But whatever the river has left to throw at us, we are ready.
0:32:07 > 0:32:10Despite frustrations and false starts, we are feeling
0:32:10 > 0:32:12battle-hardened, thirsty for big water.
0:32:15 > 0:32:17Stay on my tail, mate.
0:32:20 > 0:32:22'We hurtle through virtually nonstop rapids...
0:32:24 > 0:32:26'..and spectacular white water.
0:32:46 > 0:32:48'On this journey from the very source of the Baliem,
0:32:48 > 0:32:51'we've been hit by constant challenges.
0:32:51 > 0:32:53'The river's character has been ever-changing.
0:32:54 > 0:32:56'Sometimes gentle.
0:32:58 > 0:33:02'Sometimes a wild, tumultuous, thundering beast.
0:33:13 > 0:33:15'This is what we came here for.'
0:33:20 > 0:33:22You're mine!
0:33:22 > 0:33:24Nice, Steve.
0:33:32 > 0:33:33Oh!
0:33:50 > 0:33:53Sticking with the boys is really tough.
0:33:53 > 0:33:55It's not just that they are younger and fitter than I am,
0:33:55 > 0:33:57although that obviously helps,
0:33:57 > 0:34:00but they just... This is what they do.
0:34:00 > 0:34:03They don't get intimidated by the big stuff.
0:34:03 > 0:34:05And it's starting to get to me.
0:34:05 > 0:34:07I'm knackered.
0:34:22 > 0:34:25'As we stop to make camp, faces emerge from the forest.'
0:34:37 > 0:34:40'They are a Yali hunting party that has been following our progress
0:34:40 > 0:34:41'from a distance.'
0:34:43 > 0:34:47I think it's the village we tried to walk to yesterday
0:34:47 > 0:34:51and failed dismally. But they've come to us.
0:34:52 > 0:34:55'Their hunting trips can last weeks,
0:34:55 > 0:34:57'but it hasn't taken them that long to find us.'
0:35:14 > 0:35:17'At last, we've come face-to-face with the elusive Yali.'
0:35:31 > 0:35:34They are all intrigued, I think is the word,
0:35:34 > 0:35:36intrigued and interested as to what we are up to and what we
0:35:36 > 0:35:38are doing here.
0:35:39 > 0:35:43'But then more Yali arrive, this time with weapons drawn.'
0:36:19 > 0:36:21'New Guinea has huge mineral reserves.
0:36:21 > 0:36:25'It's home to the world's largest gold mine and the third largest
0:36:25 > 0:36:29'copper mine. But the exploitation of these resources has often been
0:36:29 > 0:36:33'at the expense of indigenous people and their lands.'
0:36:33 > 0:36:36The first 20 seconds when he came striding over here
0:36:36 > 0:36:40with his bow drawn and a look on his face like thunder
0:36:40 > 0:36:42was genuinely scary.
0:36:44 > 0:36:47'Once they realise we aren't here to steal from them or from their land,
0:36:47 > 0:36:49'the mood lifts.'
0:36:54 > 0:36:58It has an incredible spiral thread running down the length of it.
0:37:05 > 0:37:11Wow, that's beaten out of a kind of thing of fuel.
0:37:11 > 0:37:14It is basically a fuel can that's been beaten into an arrow head.
0:37:24 > 0:37:27But there aren't supposed to be any crocodiles here.
0:37:34 > 0:37:36OK, so another 10km or so downstream,
0:37:36 > 0:37:38we are going to hit crocodile country.
0:37:38 > 0:37:41'The hunters live a hand-to-mouth existence,
0:37:41 > 0:37:44'catching what they need from the jungle and the river to survive.
0:37:50 > 0:37:52'It's a tough life.'
0:37:52 > 0:37:56Isam has a nasty machete wound to his hand -
0:37:56 > 0:38:00- do you think you can do anything with it?- I'll have a look, yeah.
0:38:00 > 0:38:02'Expedition medic Aldo
0:38:02 > 0:38:05'strips away the old rags and moss they've used as a dressing.'
0:38:11 > 0:38:12You can see there...
0:38:14 > 0:38:16..it's actually just the skin,
0:38:16 > 0:38:19it doesn't look like it's gone down into the tendon.
0:38:19 > 0:38:22The main thing is to clean it up and dress it.
0:38:22 > 0:38:25'The nearest medical help is many days away.'
0:38:25 > 0:38:27It may sound like an exaggeration,
0:38:27 > 0:38:30but a wound like this out here would definitely get infected.
0:38:30 > 0:38:35So Aldo, with just a little bit of modern antiseptic and cleaning
0:38:35 > 0:38:39and dressing, could actually have saved this guy's hand.
0:38:41 > 0:38:45'These Yali hunters don't seem interested in heading for a new life
0:38:45 > 0:38:47'in the towns or working in the mines.
0:38:48 > 0:38:49'These jungles are home.
0:38:57 > 0:39:00'The next morning is potentially our last in the Lower Gorge.'
0:39:10 > 0:39:15This felt like the finest king-sized bed in history.
0:39:15 > 0:39:17Look at that, breakfast in bed.
0:39:21 > 0:39:24The butterflies here are some of the most exquisite you'll see
0:39:24 > 0:39:27in the whole world, and the biggest as well.
0:39:27 > 0:39:31The butterflies are being drawn in by our clothing we've got hanging
0:39:31 > 0:39:35out to dry. They are landing on it and extending that long proboscis
0:39:35 > 0:39:39or tongue and lapping up the minerals that's coming out of our
0:39:39 > 0:39:41crusty old sweat.
0:39:41 > 0:39:45If you watch carefully, you can see the excess fluid like that
0:39:45 > 0:39:47being excreted from the back end of the abdomen.
0:39:47 > 0:39:50The only thing they want is the salt.
0:39:55 > 0:39:58'We are now on the final stretch of the Lower Gorge.
0:40:05 > 0:40:06'We start early.
0:40:11 > 0:40:14'The river gets wider and slows.
0:40:14 > 0:40:16'We are leaving the mountains behind.
0:40:18 > 0:40:23'And then ahead, we can just make out the smoke of a fire - South Gap.
0:40:25 > 0:40:28'We've arranged for motorised longboats to meet us here
0:40:28 > 0:40:30'to take us on to the coast.'
0:40:43 > 0:40:47When I think about what we've done over the last three weeks,
0:40:47 > 0:40:49the territory we've been through,
0:40:49 > 0:40:52the amount of distance we've covered,
0:40:52 > 0:40:54it's epic.
0:40:54 > 0:40:56You know, we've already done something massive.
0:40:58 > 0:41:00The clouds are rolling in...
0:41:01 > 0:41:05..and the mountains are going to disappear pretty soon.
0:41:05 > 0:41:06Just one last look.
0:41:11 > 0:41:14'The long stretch to the coast would take weeks in kayaks and there's
0:41:14 > 0:41:17'the small matter of the monster crocs.
0:41:17 > 0:41:19'Only Aldo and I will continue south to the sea.
0:41:21 > 0:41:25'The river team will be heading back to civilisation.'
0:41:25 > 0:41:31# I go down to the river tonight... #
0:41:31 > 0:41:33'We got through the wild water in one piece.
0:41:36 > 0:41:41'As did a guitar, which they smuggled all this way.'
0:41:41 > 0:41:47# Down to the river we'd ride... #
0:42:02 > 0:42:05This is probably the last chance I'll have to splash around in the
0:42:05 > 0:42:09river like this. Much downstream of here and we are in croc country.
0:42:14 > 0:42:17'This is the last leg of our journey.
0:42:20 > 0:42:24'We've 200km ahead of us through croc-infested swamp,
0:42:24 > 0:42:26'home to the Asmat people,
0:42:26 > 0:42:30'renowned warriors and once famous for being headhunting cannibals,
0:42:30 > 0:42:33'before we reach our goal - the Pacific Ocean.
0:42:36 > 0:42:38'As we travel further downstream...
0:42:39 > 0:42:41'..the landscape and the river change.
0:42:43 > 0:42:46'We are now meandering through lowland jungle.'
0:42:55 > 0:42:58These trees are mangroves and a lot of these plants
0:42:58 > 0:43:01are tremendously saltwater tolerant.
0:43:01 > 0:43:04They have to deal with the fact that the water level here is going up
0:43:04 > 0:43:06and down twice a day.
0:43:06 > 0:43:10Because we are now in the tidal reaches of the Baliem.
0:43:12 > 0:43:19This is one of the last huge, unspoiled rainforests left on Earth.
0:43:20 > 0:43:24It is one of the most biodiverse forests there is on the entire planet.
0:43:24 > 0:43:28The amount of species living here is extraordinary.
0:43:35 > 0:43:39It's a massive colony of flying foxes,
0:43:39 > 0:43:43giant fruit bats, and they are truly giant -
0:43:43 > 0:43:46the wingspan is well over a metre.
0:43:46 > 0:43:48'These bats are the largest in the world.'
0:43:51 > 0:43:55There must be 4,000 or 5,000 bats in this colony.
0:43:55 > 0:43:59It's absolutely huge, it goes all the way back into the forest.
0:43:59 > 0:44:03And although they look like giant vampire bats,
0:44:03 > 0:44:04actually they're feeding on fruit.
0:44:04 > 0:44:07And these are incredibly important animals,
0:44:07 > 0:44:12they're one of the most vital dispersers of seed in the rainforest,
0:44:12 > 0:44:16so much of the trees and the forest that we're seeing around us is made
0:44:16 > 0:44:18possible because of bats like this.
0:44:20 > 0:44:23And they have remarkable mechanisms in their feet.
0:44:23 > 0:44:27When we relax, our hands fall open.
0:44:27 > 0:44:30But when they relax, they come closed like this, so they are
0:44:30 > 0:44:33always gripping. They have long claws at the end of each one
0:44:33 > 0:44:37of their toes and just one of those is enough to hook on to the branch
0:44:37 > 0:44:41and they can just hang there all day long with no effort whatsoever.
0:44:43 > 0:44:46'After two days travelling through jungle,
0:44:46 > 0:44:48'we get our first glimpses of people living by the river.
0:44:51 > 0:44:52'We are in the land of the Asmat.
0:44:56 > 0:44:58'Many of the Asmat remained uncontacted
0:44:58 > 0:45:00'at the end of the 20th century.
0:45:00 > 0:45:03'There are probably wild corners that have yet to meet the modern world.
0:45:04 > 0:45:08'They have lived here for a staggering 30,000 years.
0:45:08 > 0:45:11'But how are they coping with the 21st century?
0:45:11 > 0:45:14'What impact is it having on their ancient traditions?'
0:45:14 > 0:45:18We are just pulling in to a village called Yaosakor.
0:45:18 > 0:45:22This is the first settlement we've actually seen marked on a map
0:45:22 > 0:45:25for about ten days, since we left the highlands.
0:45:25 > 0:45:28This looks like the traditional long house up ahead.
0:45:31 > 0:45:34'There are Asmat villages scattered all through the jungle,
0:45:34 > 0:45:36'but Yaosakor is one of the largest.'
0:45:39 > 0:45:41THEY SPEAK LOCAL LANGUAGE
0:45:44 > 0:45:47No prizes for guessing how the people of this village
0:45:47 > 0:45:49make their living,
0:45:49 > 0:45:53or what the main food source is here.
0:45:53 > 0:45:56'The village is built on two metre-high stilts to protect
0:45:56 > 0:46:00'the houses from river floods, with raised walkways connecting
0:46:00 > 0:46:03'private dwellings and communal buildings.
0:46:03 > 0:46:06'The long house is the traditional centre of the village
0:46:06 > 0:46:08'where the elders hold important meetings.
0:46:10 > 0:46:13'As we've seen throughout Papua,
0:46:13 > 0:46:15'elders are the most respected members of the community,
0:46:15 > 0:46:18'guardians of their culture.
0:46:18 > 0:46:20'Ernes is one of the village elders.'
0:46:59 > 0:47:03The river is at the heart of everything they do.
0:47:03 > 0:47:05They come from the river and when they die,
0:47:05 > 0:47:07they go back to its source.
0:47:08 > 0:47:12'The river may be a vital part of Asmat life and culture,
0:47:12 > 0:47:15'but its murky waters hide real-life monsters.
0:47:16 > 0:47:18'The saltwater crocodiles that live here
0:47:18 > 0:47:20'are the largest reptiles on earth.'
0:48:00 > 0:48:04Quite often actually, crocodiles are seen as a symbol of great power
0:48:04 > 0:48:06and there's a lot of respect for them.
0:48:06 > 0:48:09Here in this village, that's definitely not the case -
0:48:09 > 0:48:11the crocodile is pure evil.
0:48:14 > 0:48:18'Just seven years ago, the village was terrorised by a huge crocodile.'
0:48:20 > 0:48:22Oh, my goodness.
0:48:23 > 0:48:26It's the biggest croc skull I've ever seen in my life.
0:48:34 > 0:48:37This is from a saltwater crocodile,
0:48:37 > 0:48:41which is the biggest species of reptile, the biggest species of crocodilian.
0:48:41 > 0:48:43Look at the size of those teeth there.
0:48:43 > 0:48:48This was a nearly five-metre long crocodile.
0:48:48 > 0:48:52I kind of quite struggle to lift it with my hands,
0:48:52 > 0:48:56but look how broad the skull is.
0:48:56 > 0:49:00A crocodile like this could weigh three-quarters of a tonne.
0:49:00 > 0:49:03It's often said these rivers in New Guinea have the largest crocodiles
0:49:03 > 0:49:07in the world and this proves that is absolutely true.
0:49:19 > 0:49:2117 people and then one
0:49:21 > 0:49:25of the people here killed it with a spear, just like that one.
0:49:25 > 0:49:28It was basically eating its way through the village.
0:49:28 > 0:49:32When it was alive, this would have been a true monster.
0:49:32 > 0:49:35It really does bring home how difficult life must be
0:49:35 > 0:49:37in a village like this.
0:49:37 > 0:49:39Knowing that every time you go down to the water's edge,
0:49:39 > 0:49:42there could be something like this waiting.
0:49:47 > 0:49:51'Although saltwater crocodiles are legally protected here,
0:49:51 > 0:49:54'the Asmat are allowed to hunt and trade them in small numbers.
0:49:59 > 0:50:00Just a few days ago,
0:50:00 > 0:50:03'the villagers caught another one and it's still fresh.
0:50:03 > 0:50:04'Well, nearly.'
0:50:07 > 0:50:08Ugh.
0:50:11 > 0:50:13'Three days festering in the hot,
0:50:13 > 0:50:16'humid Papuan climate, and the carcass reeks.
0:50:19 > 0:50:22'I've been an animal lover all my life and I'm particularly fascinated
0:50:22 > 0:50:24'by reptiles like crocodiles,
0:50:24 > 0:50:26'so seeing this skin and rotting skull
0:50:26 > 0:50:28'is difficult for me to stomach.'
0:50:43 > 0:50:44'It may not have been a man-eater,
0:50:44 > 0:50:48'but a crocodile this size will provide the Asmat with fresh meat
0:50:48 > 0:50:52'to feed the village and its skin can be traded for hard currency.'
0:51:12 > 0:51:15'My ideals of animal welfare and conservation seem
0:51:15 > 0:51:19'pretty out of place here, where people live their lives
0:51:19 > 0:51:22'alongside predators with such lethal potential.'
0:51:23 > 0:51:29Obviously it's sad that an animal of that size has been killed,
0:51:29 > 0:51:34but at the same time, if you live in a place like this and an animal
0:51:34 > 0:51:40takes 17 of your friends and family from the river then, you know,
0:51:40 > 0:51:42obviously you're going to kill it.
0:51:44 > 0:51:46THUNDER
0:51:53 > 0:51:57'As the heavens open, the Asmat all come together.
0:52:04 > 0:52:06'Normally the long house is men only.
0:52:07 > 0:52:10'But today the whole village is here to sing,
0:52:10 > 0:52:13'dance and share their ancient tales.
0:52:18 > 0:52:20'To help celebrate the village gathering,
0:52:20 > 0:52:21'a feast is being prepared.
0:52:23 > 0:52:26'And this time it's not crocodile,
0:52:26 > 0:52:29'but one of the village's own pigs that's about to be slaughtered.'
0:52:35 > 0:52:37THEY CHANT
0:52:39 > 0:52:40PIG SQUEALS
0:52:46 > 0:52:49'The pig will provide enough food for all 12 of the village clans
0:52:49 > 0:52:52'and Aldo and I are honoured to be included.
0:52:57 > 0:53:00'Before the feast begins, somewhat incongruously,
0:53:00 > 0:53:02'the village head says prayers.'
0:53:15 > 0:53:18'Missionaries have been converting the Asmat and other Papuan tribes
0:53:18 > 0:53:21'to Christianity since the 1950s.
0:53:21 > 0:53:25'The missionaries persuaded many tribes to leave behind headhunting
0:53:25 > 0:53:26'and cannibalism.'
0:53:38 > 0:53:41'Although much of Yaosakor is nominally Christian,
0:53:41 > 0:53:44'traditional animist beliefs are still the dominant force.'
0:53:45 > 0:53:46Mmm.
0:53:48 > 0:53:49- Is it good?- Mmm.
0:53:53 > 0:53:55'Their traditions run deep.
0:53:55 > 0:53:59'Often Christianity has simply been incorporated into their older beliefs,
0:53:59 > 0:54:03'beliefs that everything in nature possesses a spiritual force.
0:54:09 > 0:54:11'The drumming continues late into the night,
0:54:11 > 0:54:16'the elders singing ancient Asmat poems which can last for many days.'
0:54:20 > 0:54:25It's quite late now in the long house and the drumming finished
0:54:25 > 0:54:26a little while ago.
0:54:26 > 0:54:29But there's still lots of people milling around, sitting,
0:54:29 > 0:54:34chatting, sitting around fires and this will go on all night long.
0:54:34 > 0:54:36I guess I'm probably not going to get
0:54:36 > 0:54:38an enormous amount of sleep here.
0:54:38 > 0:54:43But it's one night in a lifetime so I'm just going to enjoy it.
0:54:56 > 0:55:00The Asmat's main contact with the outside world has been through art.
0:55:00 > 0:55:04Their carvings are treasured by anthropologists and collectors.
0:55:06 > 0:55:10Beyond Yaosakor, the Asmat region is a morass of tangled forests.
0:55:11 > 0:55:14Most settlements are just a few shacks.
0:55:14 > 0:55:17If the modern world was going to change the Asmat anywhere,
0:55:17 > 0:55:18it would be here.
0:55:19 > 0:55:23But life in Yaosakor continues as it has done for generations.
0:55:23 > 0:55:27You'd have to travel 100km to get any signal for that phone.
0:55:28 > 0:55:31'It seems to me, a few tin roofs aside,
0:55:31 > 0:55:33'the modernity hasn't got much appeal.
0:55:33 > 0:55:36'My new friends say they like things just the way they've always been.'
0:55:49 > 0:55:53'We are now just hours away from completing our month-long,
0:55:53 > 0:55:58'500km expedition from the central highlands to the Pacific Ocean.'
0:56:02 > 0:56:04Four weeks ago, we were stood up at Habema,
0:56:04 > 0:56:08the source of the Baliem and it was a trickle,
0:56:08 > 0:56:10a hop, skip and a jump across it.
0:56:10 > 0:56:14And now coming to the sea at the end of the journey some four weeks later
0:56:14 > 0:56:18and it's 4km or 5km wide.
0:56:18 > 0:56:19Look at the size of it.
0:56:21 > 0:56:24'There's no doubt our journey has been a challenging one.
0:56:24 > 0:56:27'It's proved to be much tougher than I ever imagined
0:56:27 > 0:56:29'and things have rarely gone according to plan.'
0:56:31 > 0:56:34The history of exploration and expeditions
0:56:34 > 0:56:37is a history of cataclysmic failures.
0:56:37 > 0:56:43Even the very greatest of explorers had impossible challenges.
0:56:43 > 0:56:45You know, Shackleton and Scott,
0:56:45 > 0:56:48probably the two best-known British adventurers,
0:56:48 > 0:56:51are best known for their failures and...
0:56:53 > 0:56:57..in those terms, actually this has been a success.
0:56:58 > 0:57:01We have travelled from the source to the sea and been the first people
0:57:01 > 0:57:03ever to do it.
0:57:03 > 0:57:07Admittedly, more of that has been done in motorboats and helicopters
0:57:07 > 0:57:08than I would have chosen.
0:57:10 > 0:57:13But, I think it's the nature of expeditions that...
0:57:14 > 0:57:17..there are going to be challenges. And if there aren't,
0:57:17 > 0:57:20then it probably doesn't qualify as an expedition.
0:57:25 > 0:57:27'Finally, our goal is in sight.'
0:57:35 > 0:57:36It's the sea!
0:57:39 > 0:57:43'After everything we've been through, all the challenges we've had,
0:57:43 > 0:57:45'to come down here,'
0:57:45 > 0:57:47all of a sudden it feels like every single bit of it
0:57:47 > 0:57:48has been worthwhile.
0:57:50 > 0:57:52This was all about doing the first ever source to sea
0:57:52 > 0:57:55of the Baliem River, it was all about the challenge.
0:57:55 > 0:57:58But it's just become so much more than that.
0:57:59 > 0:58:03It's been truly remarkable to get an understanding of just how
0:58:03 > 0:58:08this mighty river has breathed life into this corner of the world.
0:58:08 > 0:58:10To see how it shaped the landscape,
0:58:10 > 0:58:13created a habitat for unique wildlife
0:58:13 > 0:58:16and how it's made a home for the ancient tribes who thrive
0:58:16 > 0:58:18along its banks.
0:58:19 > 0:58:24This place is always going to have a really special part of my heart.
0:58:25 > 0:58:26And look at that!