The Brazilian government is seeking to repave the almost impassable BR-319 route between Porto Velho and Manaus. But the plan is controversial because the 900km (560 mile) road cuts right through the Amazon rainforest. BBC journalist Ben Sutherland has been travelling along the route.
4 NOVEMBER: END OF THE ROAD
As I prepared to leave Manaus after this stunning adventure through the Amazon rainforest, I considered what the BR-319 would look like were we to drive it once more in two years' time.
Communities on the route of the BR-319 are isolated and few in number
My guess is that it will be very different - a smooth ribbon of pristine bitumen. Certainly, I doubt people using it will still have to get out their cars and physically put a bridge back together just to drive across.
The debate over the repaving is really the dilemma facing the planet in microcosm.
Why, exactly, rebuild this road? The people along it are isolated, yes - but as our journey has just shown, there are hardly that many of them.
To drive growth? Well, Manaus is doing very well already - and studies suggest that if anything, the road will trigger an influx of unemployed migrants that the city is completely unprepared for, ultimately doing more harm than good to what is currently Brazil's third largest economic hub.
So why go ahead? The answer is simply that it is a popular idea.
The environmentalists themselves admit as much. Professor Fearnside of the National Institute for Amazon Studies says that one reason people in Manaus back it is because they think they will be able to drive down it straight to Copacabana beach in Rio.
They are, of course, wrong - just to fly such a distance takes around four hours - but the important thing is the public perception.
There are many fears about the impact of repaving the BR-319
To preserve the rainforest requires strong government, a willingness to take the decision not to exploit the economic potential of the land currently occupied by the trees. But to stay in power in a democracy, governments have to continue to promise growth.
Build a road that will be popular with people or risk losing power? The choice is obvious, and it is not as if trees have votes.
And this is the problem that faces the governments of the world as they prepare to meet in Copenhagen in December.
Many will undoubtedly seek tough measures to fight climate change.
However, it is something of a stand-off. Whatever is agreed can be successfully implemented only if everyone else agrees to it too.
But if a government signs up to strict guidelines and the public blames these for any subsequent downturn, what leader will be able to resist the temptation to abandon the treaty? Even if they did, what opposition party could stop themselves from promising a rethink if they got into office?
Until environmental protection ranks higher on people's priorities than their own individual economic situation, it is likely more forests will disappear, more land will be degraded - and more roads like the BR-319, with all its feared consequences, will be built.
3 NOVEMBER: OPPOSING THE ROAD
It was perhaps unsurprising that most of the people we encountered along the ruins of the BR-319 were firmly in favour of its being repaved.
Isolated as they were, they were desperate for the new economic opportunities and governmental infrastructure the new road would bring.
Professor Philip Fearnside fears major environmental damage
To get the opposite view, you have to go into the city - to a place like the National Institute of Amazon Studies in Manaus, and talk to someone like Philip Fearnside.
Professor Fearnside is one of the BR-319's staunchest critics: in his office is a picture of him drawn by a cartoonist in a Brazilian newspaper, his hand raised at a bulldozer, his luxuriant moustache bristling.
He has spent many years studying the impact of road building on the Amazon rainforest - which is, he says, that without aggressive government protection, 33% of the rainforest will be gone by 2050.
And he fears that the current government will ultimately prove anything but aggressive.
"The problem is that you have to have some sort of legal way to decide not to do things," he said.
"It's one thing for a minister to say they're not going to build side roads, but it's not yet the time to build those side roads anyway. Wait until the BR-319 is built and the people move in, and a few years later there will be a clamour from the municipal governments to have the roads.
"What is the mechanism that you're going to stop it with legally?"
In particular, he thinks a new road will open up the area west of the Purus river - there are large natural gas fields there, and the lack of a dry season makes it prime territory for planting oil palm for biodiesel.
Mario Cohn-Haft says the Amazon's wildlife will be affected
Meanwhile it would also put pressure on the BR-174, which is the road to Venezuela out of Manaus. In all, he estimates around half of the rainforest could be opened up.
This is obviously of huge concern to those who study the Amazon and the creatures that live within it - people like Mario Cohn-Haft, also of the Amazon Studies institute.
It was he who discovered the first jay ever found in the Amazon, earlier this year. He believes there could be up to 1,700 species of bird so far undescribed.
"We don't have any precedents for the repaving of a road and not having massive destruction along it over the subsequent years.
"So there's nothing but pure optimism to think that the same thing isn't going to happen along the BR-319."
The problem is made particularly acute because the BR-319 cuts right through what is known as an "area of endemism" - the only place that certain species can be found in the world.
"Destruction of the forest along that ends up eliminating a huge proportion of all the habitat available to the creatures that only occur there."
But it is not as if these concerns are not known - the cartoon on professor Fearnside's desk is testament to that.
Despite this, the road remains a popular policy for government ministers: transport minister Alberto Nascimento (see entry for 3 Nov) has staked his position on getting it built.
The irony is plain. To the frustration of the environmentalists, the paper their reports are printed on is proving to be a waste of trees.
2 NOVEMBER: MAN WITH A VISION
After spending so long meeting the people whose lives will be changed by the repaved BR-319, it was time to meet the man whose vision it is.
Alfredo Nascimento is his name. He is Brazil's transport minister, a stocky, dark-haired man with a reputation as a hard-hitter in the government.
The minister says a repaved BR-319 will not aid destruction of the rainforest
It was apt that we met him at the offices of a publishing company run by his son, because this project is his baby now.
"This will show the rest of the world that it is possible to develop and yet not destroy," he told me.
Although the repaving enjoys widespread support amongst the populations of Amazonas and Rondonia - the two states the BR-319 links - studies by environmentalists differ.
A group based in Manaus say that the best way to preserve the integrity of the rainforest is to leave the road alone.
They argue that it is sheer inaccessibility which prevents further deforestation along the route, as the landless poor who would otherwise move in and occupy it simply cannot get there.
The journey is just too difficult.
This view appears to be supported by the country's Environment Minister Carlos Minc, who was so insistent that a proper scientific study be undertaken that he forced the issue as far as Brazil's High Court.
But Mr Nascimento said that in his view, the biggest risk to this part of the forest is keeping the road in its current state.
"People will go there anyway," he said.
"But we would have strong monitoring of that area, with people that are linked to environmental agencies in Brazil, and the police."
I was curious about the sheer manpower this would take.
Having now travelled the length of the road myself, I have seen how isolated the communities are who live along it.
The BR-319 cuts its way through some of the Amazon's most remote regions
I can't imagine how difficult it must be to have any idea what is going on inside that vast canopy.
The total number of people to protect it? "200," Mr Nascimento calmly stated.
I indicated that that did not seem a very big number for a road 900km (560 miles) long.
He insisted that that figure was only for people from the environmental agencies - and did not include the police or the federal authorities.
When asked how long all this would take to set up, I was told it would be in place by 2011.
But he gave me a wry smile when asked what he thought the environment minister's response would be to the same question.
"Only the environment minister can answer that," he said, cautiously.
"But the president understands that the people of Amazonas shouldn't be punished for preserving the Amazon," he added.
1 NOVEMBER: PASSING TRADE
We drove the literal last few metres of the BR-319 this morning.
We had spent the night in the small town of Careiro, a settlement built around the ferry terminal on the southern side of the Amazon river. The BR-319 simply runs out at the water's edge.
The town's economy relies on its ferry service to Manaus
Careiro is clearly very poor. The main street is strewn with litter and stray dogs.
The only places open are a shop selling beer by the crate and a number of small fried-food kiosks. Outside one, an elderly man sits at a plastic table, watching the same music video over and over again.
"Sexy boy, I want your love," the singer endlessly repeats at him.
The song is in the Bahia style, named after the north-eastern state in which it originated and one of the most popular type of music here.
While some younger fans love it, others find its combination of up tempo beats and somewhat unchallenging lyrics exceedingly irritating.
Eventually, the kiosk owner has to close, and eases the man away from his seat.
We take our leave too, heading for the wooden hostel we are booked in for the night.
Its target market is people like us who have to stay overnight because we need to catch the ferry in the morning. Few people stay longer than they have to in Careiro.
In contrast, Manaus, the city that glares at it from over on the opposite bank, is thriving.
Historically, it has always been one of Brazil's wealthiest cities.
This money came originally from rubber - being both in the heart of the rainforest and with access to the waterway system via the Amazon, the settlement was ideally placed to capitalise on the boom in latex.
While this has now fallen away, the city's economy is driven principally by a huge government-sponsored industrial zone.
We saw much of this in evidence as we drove out of the harbour, passing the Brazilian HQs for brand name after brand name: Samsung, Nokia, Sony.
It is through this industrial zone that the BR-319 will one day run: with the repaving will come a vast bridge spanning the Amazon.
Where that will leave the town of Careiro, where the only economic activity is based around a ferry service that will instantly become obsolete, is anyone's guess.
31 OCTOBER: 'FISHBONE EFFECT'
At Igapo Acu, the village in which we spent the night, it is not too much of a romanticism to say that the main sound that can be heard is children's laughter.
This is partially because the village is so small that any sound is readily audible. But there is more to it than that, for the children have two special playmates - a pair of river dolphins.
The dolphins respond to the sound of a fish being slapped on the surface
The dolphins, named Beto and Zelia - the latter a reference to a former Brazilian finance minister who was often pregnant while in office - have learned to respond to the sound of someone rhythmically slapping a fish on the surface of the water.
They then come up and make swift grabs at the fish as the children try to jump on their backs. It is a delightful scene.
But should the BR-319 be repaved, the open harbour in which it occurs will be replaced by a long bridge.
Adilson Serra Barreta, who helped catch Beto when he was still very young, said the Icupo Acu he knows will soon be gone.
"We have very peaceful village - no crime rate, no drugs," he told me. "People all know each other, and we have easy access to food and crops.
"We do fear the reopening of the BR-319 will change this lifestyle, and make our lives worse."
Scientists fear that local wildlife be threatened by BR-319 medication
"At the same time, we don't have access to government services - we don't have enough education and health services are poor."
We left and continued our journey, at one point pausing to climb one of the tall telecommunication masts that line the route.
From around halfway up, the view looked out over the top of the rainforest canopy - vast swathes of green stretching away to the horizon, broken solely by the BR-319 itself.
At this vantage point, it is easy to see why scientists are so concerned about the repaving, and the so-called "fishbone effect" - the addition of side roads to a newly-profitable main route - which would accompany it.
While repaving an already existing road may not, in theory, be all that damaging, the side roads can be absolutely devastating. The worst predictions say that projects like this could lead to 33% destruction of the rainforest by 2050.
Knowing that a scientific research station was nearby, we took a chance to drop in and meet some of the people specialising in rainforest studies in the field, ahead of our planned meetings with others in Manaus.
We were disappointed this time - they were working deep in the forest and too far for us to trek - but the visit was not wasted as it gave us the chance to meet Theresa, who manages the cooking and cleaning at the base.
Aged 62 and not much more than 5ft (1.52m) tall, she has an extraordinary life story. She gave birth to her first child at the age of 14 and had nine more.
Theresa said people lack self-control
They in turn provided her with 24 grandchildren and, subsequently, 15 great-grandchildren. The eldest of these, at 15, is expecting her first baby, so Theresa will soon be a great-great grandmother.
She also spent some part of her life as a midwife and helped deliver a further 32 babies.
"Young people today party too much after giving birth," she told us.
"They go out straight away, and then they call me when they feel ill. They should look at pigs and cows; they don't get up after giving birth until they're ready."
She also said people lack self-control these days and that she would not hear of being told not to hit her children to discipline them.
"Only one cockerel crows in my house," she insisted.
I considered that opinion on this controversial road is one thing, but sometimes the opinions of the old towards the young, whether in central London or the heart of the Amazon, have a certain universality.
30 OCTOBER: PRECARIOUS POSITION
Today we saw the worst - and, not coincidentally, the best - of the BR-319.
Everyone held their breath as the vehicles went across the bridge
No sooner had we started than we reached one of the many rickety wooden bridges which line this route, in various states of disrepair.
And this one was in an absolutely appalling state - by far the most dangerous of the bridges we had encountered so far.
Made of cheap wood that had warped and split in the sun, the 20m-long bridge crossed a sheer drop down into a shallow river.
The way across was on twin tracks of timber planking barely wider than our 4x4's tyres. Unfortunately, these had warped and split, coming completely away in places.
Our driver, Luiz Clayton, had to get out, pick them up and put them back in place.
Subconsciously, everyone held their breath as he slowly eased the vehicle across. We only let it out again once all four wheels were back on the broken tarmac of the road.
Ben finds the remains of a VW Campervan alongside the road
We did not wish to end up like a number of the wrecks we have already seen half-entombed in undergrowth by the roadside.
But it is this very difficulty of negotiating the road that also makes some places along it very special indeed.
Not much further on, we crossed another of these bridges - this time over the Rio Novo - and stopped by the river below to have a drink. And the scene that we found was spectacularly beautiful.
On the bank were huge numbers of butterflies; some brightly coloured as summer flowers, others camouflaged to resemble decaying leaves.
Meanwhile, around 15 large bees were swarming over a bar of presumably sweet-smelling soap - seemingly the only evidence, apart from the bridge itself, that human beings had ever been here.
A baby crocodile was discovered bathing in one of the huge potholes
The river flowed slowly past; the trees hung over the water as if their branches were relaxing.
But it was perhaps only because the road was so bad - at one point, we found a baby crocodile bathing in one of the huge potholes - that such a scene of natural beauty could continue to exist.
Would it have been improved with the addition of traffic rushing over a newly-concreted bridge?
In its hurry to develop like the rest of the world, it would be a shame if Brazil lost the places like this that make it a country so unlike anywhere else.
29 OCTOBER: ROAD TO NOWHERE?
The battered car in Marle Schroder's driveway was only the second vehicle we saw today. The first - some three hours earlier - had been her husband's.
Such is the isolation on this road.
Marle Schroder and her family are doing well but want to do better
The Schroders - whose origins go back to Germany - have run a cattle ranch along the side of the road, at around the halfway point from Porto Velho to Manaus, since 1991.
While at first they struggled, they now farm quite profitably. Their ranch house is an impressively-sized timber building, and there are several other small houses around - home to chickens, pigs, and the occasional macaw.
They also own the small but tranquil lake that lazes alongside the cattle pasture.
And Marle thinks they could be doing better yet. She wants the BR-319 to be rebuilt so that their cows can be transported along it at all times of the year, rather than having to wait out the six-month rainy season that renders the road utterly impassable, and that they themselves insure against by having the house raised off the ground on a base of tree trunks.
Cattle ranchers are the only ones who seem to be making a profit
She does concede she has concerns: a repaved road may bring land-grabbers seeking to take her ranch. She has heard of people who have been killed over this, and is worried her family may be targeted because they have been so successful.
But overall, cattle ranchers are the exception, the one business that can be seen thriving along this route.This is in contrast to the restaurants, hotels and garages that sprang up in the 1970s, when the road was first paved - hoping to take advantage of the new traffic.
As the road crumbled away, so did their profits.
Earlier we had taken a look around a long-abandoned petrol station that was utterly symbolic of this decline.
Eric stumbles across the ruins of a petrol station by the side of BR-319
The panels that made up the flying canopy had rusted and collapsed to the floor. A storage hut had a 3m (9ft 10in) high termite nest around its door. And the pumps had been smashed in and had their internal piping out, like eviscerated metal corpses.
Perhaps most symbolically, a tree was now growing through the kiosk where customers used to buy petrol - but in fewer and fewer numbers as the poorly-constructed tarmac fell apart.
We have seen dozens of these skeletal buildings so far along the BR-319; serving as a warning, perhaps, to those desperate to exploit the economic potential of a repaved road.
28 OCTOBER: THE GREEN HELL
There are so many unknowns around when and if the BR-319 repaving goes ahead. But one thing that is for certain is who will undertake the work - the country's national army.
Having only so far glimpsed them behind the wheels of their various construction machines along the road, today we got to meet them up close.
This unit of Brazil's national army tries to take care of the Amazon rainforest
We had spent the night in a school in the settlement of Realidade. We had been intending to camp, but some of the local residents allowed us to spend the night in the local school.
There were no teachers around because the next day was payday and they had to travel down the BR-319 to Humaita to collect their wages. a round trip of six hours.
In the morning we were awoken by the noise of 15 Mitsubishi 4x4s thundering past, all being driven by soldiers in army fatigues.
But it turned out the battle they were off to fight was the ancient one between man and nature - and, on this occasion, it seemed they were on nature's side.
They were on their way to lay the first of 27 markers, deep in the rainforest, that would mark the boundary of the protected natural reserve.
These markers are a condition of the repaving project. It cannot begin without them in place.
Since this first marker was therefore a historic moment for the project, we decided to go along to observe - which involved an hour-long trek through the thick jungle, navigating via small cuts put into the trees by the huge machetes the army use to cut through the almost solid walls of vegetation.
By the time we found them, we were exhausted, both from the trek and from the intense humidity. It turned out we were not the only ones.
The soldiers fell the trees so they can create essential markers for satellites
"We call this the green hell," Maj Nilton of the Brazilian army told us, above the jagged roar of a chainsaw.
However, it was not because of any antipathy towards the forest that they were felling trees.
Instead, they were making a clearing big enough to pick up the exact co-ordinates of the boundary from a satellite. Maj Nilton called it a "window to the sky".
It may seem an extreme measure just to ensure a good reception on the sat-nav, but Maj Nilton explained that it was essential.
"We must mark the point correctly, otherwise the people who want to explore the area for their business will complain," he added.
With some of the trees in this part of the Amazon worth up to $150 (£91) per cubic metre, the temptation is clearly strong for the legal loggers to push as close to the protected areas as they can.
Whether these markers will keep out the illegal ones - especially if the road is built - remains to be seen.
27 OCTOBER: LOCAL FEARS
Leaving the town of Humita this morning, we briefly left the BR-319 and joined the Transamazonica, the famous road that runs east to west across Brazil.
The BR-319 is being extensively developed by Brazil's government
Looking like a raw scar through the forest, this road is also undergoing serious redevelopment by the Brazilian army.
Our vehicle was frequently enveloped in clouds of thick dust as it passed by the huge, skeletal machines pounding the ground to make it suitable for repaving.
As we rejoined the BR-319, I was struck by an evocative sight: we saw two vultures gorging on a cow carcass on the side of the road.
Two more watched on a burned tree stalk, wings folded and silent, like a pair of black-cowled monks, wondering perhaps when they would get to join the feast.
Soon after we were met by the side of the road by the Indian villages of Tucuma, who had travelled out to meet us in their brightly-painted flatbed truck.
Around 30 of them had crammed in the back, many of them children - despite the tropical rainstorm that engulfed us.
The Indians' main concern is that rebuilding the BR-319 will attract more people into the area with designs on their land.
The local people fear the road will attract land developers
They want proper zoning, whereby the area they live in is formally protected by law.
"Many land grabbers operate in this area," said one.
"This has happened to us before. This is our land. We need to have the rights to it.
Their chief, Luiz Apurina, was reluctant to say much about the BR-319 either way: "My feelings are positive," he said guardedly.
Our interview was cut short by a huge tropical downpour - the first we have experienced since the journey began - which sent the Indians back hiding under a tarpaulin, and us back into the 4x4 in order to save our equipment.
But for the first time, it seemed to me, we had met people less than convinced about the benefit of repaving this road.
As we began to head further into the forest, I doubted they would be the last.
26 OCTOBER: JOURNEY FOR REAL
Today was it - the day we finally left Porto Velho and properly began the journey down the chewed-up remnants of the BR-319.
But before that, there was one last visit to make. We wanted the official view from Porto Velho on the prospects for the road.
And we could not have got a more fervent answer than that of Cletho Muniz de Brito, minister for environmental development for Rondonia state.
"For Rondonia and Amazonas, building the BR-319 will mean what the Channel Tunnel meant for Britain," he said.
The journey began for real when we joined the BR-319 in Porto Velho
In saying this, he did not mean it would allow the people of the two states to spend a day shouting in poorly-remembered French and stocking up on duty free.
Rather, he was referring to how it will be possible to greatly improve trade relations because goods will no longer require a slow and expensive ferry service between the two cities.
A paved BR-319 would cut the travel times for food, for example, from six days to just eight hours.
The minister contends that the road is essential - although perhaps it should be noted he has the word "development" in his job title - rather than, as in other Brazilian states, ending with the word "environment."
It certainly is worth pointing out that Porto Velho and Manaus are the respective capitals of Rondonia and Amazonas - states that share a border.
Imagine there being no road between London and Edinburgh, or New York and Washington.
But while it is in the city where the case may be heard the loudest, it is probably in the tiny settlement of Renascer - about two hours' drive out of Porto Velho - where it resonates the most.
Renascer is home to about 70 families, drawn to the area when the BR-319 was first opened in the 1970s.
They moved after the construction, anticipating that the road would be their route to wealth.
Instead it disintegrated - much like their hopes.
A generation or two later their offspring remain here, because there is nowhere else to go.
Due to a lack of public transport education in Renascer stops at age 12
The decision by the Ecuatur bus company to abandon its service to Manaus virtually ended public transport options.
Without public transport the children of the tiny school here cannot get a secondary education, the nearest one is simply too far away.
Consequently their education stops at 12 years of age.
Their teacher, Miss Mariah, is one of the few people they see regularly who does live in Porto Velho - who has to go to extraordinary lengths to get to the school.
Every morning she hitch-hikes in, relying on strangers simply to get to work.
It was ironic then that when we met them her children were having a geography lesson.
Proponents of the BR-319 would surely point out that unless the paving goes ahead, few of those studying will ever be likely to require such knowledge.
25 OCTOBER: OUT IN THE OPEN
It is four in the morning, and in the steaming Brazilian night we are flashing the lights of our 4x4 at a small wooden ferry on the other side of the bank of the river at the edge of Porto Velho.
There is no questionable motive for this - it is simply the only way to get the attention of the ferry crew so they can come and pick us up.
The ferry runs all night. It has to, there is no bridge. One has been proposed, but will only be constructed if the repaving of the BR-319 goes ahead.
We are up this early because we want to get to a special part of the Amazon rainforest, and hope to get a look at some of the animals there. Dawn, when they come out to feed, will offer us the best chance of catching a glimpse.
What is special is that it is not the typical high-canopied dense jungle. Indeed, there are hardly any trees, and those that do stand are barely more than 1 or 2m high.
But this is not the result of deforestation - although that is much in evidence along the way. On the contrary, this is natural savannah - a wide expanse of grasses, shrubs and ponds.
Eric Camara takes a look at the Amazon's savannah
Places like this occur where the ground is higher in the forest. This one is particularly special, as it was here that earlier this year a species of blue crow, previously unknown to taxonomy, was first identified.
Our visit is less successful in that respect. We do see a number of macaws, toucans and parakeets, as well as the footprint of a tapir - one of the largest mammals of the Amazon, which can weigh up to 300kg.
We film by the side of a picturesque pond, which proves to be a problem when halfway through a take my colleague Eric, making a piece for BBC Brasil website, is stung on the arm by a particularly vicious-looking insect. He bravely continues for a few words before leaping around and shouting in violent Portuguese. There are a number of guffaws from the watching drivers.
Cattle farming is one of the causes of deforestation - both legal and illegal
Once recording has finished we make our way back to Porto Velho. The savannah ends and the deforested areas begin, huge cows struggle for shade amongst the burned stumps of the cleared land.
On the way we meet cattle farmer Juan Gugeiro. He is is partially - and perfectly legally - responsible for some of the deforestation - Brazilian law allows farmers to clear 20% of their land, and he has done so.
"If I want to expand any more, I will have to make the land I already have work harder," he says. "A lot of farmers will tell you the same."
He is all for the BR-319, saying that the economic potential of repaving the road is massive.
And he has firm words for Western governments who criticise Brazil for not doing enough to stop farmers burning trees.
"What are Europe and the US doing to stop emissions?" he asks. "They destroyed all their forests, and now they want to tell us what to do.
24 OCTOBER: AN ALLURING CHALLENGE
It was around 1988 that the BR-319 finally became impassible.
The road that bisects the Amazon rainforest had never really been properly maintained since being built in the 1970s. Every year, the rainy season took away another layer of tarmac.
The potholes were getting deeper; with every vicious bump, more and more drivers were having their crowns knocked from their teeth and the bumpers knocked from their bodywork.
Ben Sutherland and Luiz Clayton prepare to set out from Porto Velho
Eventually, the Eucatur bus company decided that the damage the road caused their vehicles was such that it was simply not worth running along the route anymore.
Subsequently, the road was left to rot and the forest grew back all around it. Its very dilapidated status is what makes the plan to repave it into a shimmering bitumen river so controversial.
But even in its current state, what remains of the road is not completely free of traffic. Indeed, some see its very "impassible" status as a challenge.
Amongst them are the Jeep Club of Porto Velho.
Jeep clubs are very popular in Brazil. We saw one as we changed planes in Brasilia; eight or nine men of a certain age, gathered in a crowded coffee lounge, laughing together in identical T-shirts and shorts.
In other countries, this type of person would perhaps go hunting, or on a particularly nasty ramble. Here, they get into 4x4 vehicles - Jeep, or "jipe", being the Portuguese generic term - and challenge themselves to drive through everything this country's wild terrain can throw at them.
They see themselves as the last adventurers.
And as our plane climbed into the air over the deep Amazon on the final leg of the flight, it was easy to see the adventure, laid out beneath us: undergrowth like a rampant wig, mud deep enough to drown a hippo - although admittedly, one that had got very lost.
Excitement junkies they may be, but reckless they are not. Luiz Cleyton, one of the founders of the Jeep Club of Porto Velho and our driver for this journey, is a researcher on the rainforest for the university here.
"We have a passion for studying the Amazon," he says.
"Every opportunity to travel around the BR-319 is interesting. I think we will have a very good trip, and we will make the most out of what the people can teach us."
We hope so too. Sunday we make our first excursion into the rainforest, before leaving Porto Velho properly on Monday. It will be a chance for us to experience some of that adventure for ourselves - and to share it with you.
23 OCTOBER: BEFORE THE JOURNEY
The BR-319 was originally built in the 1970s, but abandoned after a decade - the military government of the time failing in its effort to develop the region.
The major part of what remains is little more than a 900km dirt track.
But this is all set to change - and the BBC is going to find out how and who will be affected.
The federal government is seeking to push ahead with plans to improve the BR-319, seeing it as key to boosting the region's economy.
Manaus is one of the country's most isolated cities, but with a permanent link to Porto Velho and the Latin American countries that lie beyond, there are hopes that some of the poorest areas of the country can be opened up for growth and development.
However, the plan is not without opposition.
Many environmental groups have raised concerns about the potential destruction the road could cause to the rainforest.
This is an area where a total of 130 military police are tasked with preventing illegal logging.
How they go about this task, and how rebuilding the road might change their approach, is just one of the stories we will be looking at once we head into the forest.
I will be travelling with my colleagues Eric Camara from BBC Brasil and Rami Ruhayem from BBC Arabic along the BR-319, documenting the lives of the people who live along it.
Ultimately, we are hoping to build a full archive of life along this hugely controversial piece of highway, before it is changed forever.
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