There is a journey across the north of Brazil that few who make it ever forget. It goes from the often-destitute farms and villages of the country’s northeast along disintegrating freeways and across the waters of the River Araguaia on rusting ferry boats. Down ragged red dirt tracks, it arrives at the frayed periphery of the Amazon rainforest, where the voyage ends.

This is the slavery road, along which thousands of poor workers are trafficked, threatened, beaten and made to work without pay on farms or down coalmines or deforesting the jungle. It has happened for decades and — despite efforts to combat it — is still commonplace in the world’s eighth-largest economy.

Since 2003, the government has rescued 44,483 workers from what it calls conditions analogous to slavery. But the numbers of slaves is unknown.

“It is an invisible crime,” said Luiz Machado of the International Labor Organization. “The victims are threatened and stay silent. It is impossible to say.”

Globally, it is estimated there are as many as 36 million slaves, according to leading nongovernmental organizations. A 1956 U.N. convention defines “slavery” as “debt bondage, serfdom, forced marriage and the delivery of a child for … exploitation.”

In Brazil, slavery is defined as forced labor, debt bondage, degrading conditions that violate human rights or overwork that threatens life or health. This wider definition, which is based on protecting dignity as well as freedom, is supported by the Human Rights Council of the UN and the International Labor Organization.

Slavery is reported across the country, from farms in the wealthy south to five-star hotels in Rio de Janeiro and factories in São Paulo. But for decades, the heart of the problem has been this well-trodden route. It leads from northeastern states such as Maranhão and Piauí, known for their poverty and political corruption, to Pará, a vast state in northern Brazil encompassing much of the Amazon rain forest.

Slavery in Brazil

Former slave Elenilson de Conceição, whose furrowed face belies his 29 years, knows it intimately after he was himself enslaved to deforest the jungle. He was not paid a cent for three months of grueling labor and slept under the stars amid a forest filled with jaguars and deadly snakes. As he retraced the route with Al Jazeera America to highlight the problem, the raggle-taggle truck stops; the caged vans barely fit for animals; the shrill ferry horn, all brought back painful memories.

It is a problem that is entrenched into the feudal culture of many of Brazil’s remotest areas. It is estimated that as many as 4.9 million people, overwhelmingly African, were enslaved in Brazil after it was colonized in 1500. For more than two centuries, vast areas of the country were ruled by all-powerful captains appointed by Lisbon who had the right to exploit natural resources — and slaves — at will.

Slavery was abolished in 1888, but land reforms forced the poor to continue to be exploited in terrible conditions on the same farms, historians say. It was only after the widespread exploitation of the Amazon began 40 years ago and Brazil’s return to democracy in 1988 that the problem was acknowledged.

Slavery in Brazil

Conceição, like many others, did not grow up understanding the concept of slavery. Instead, many of his parents’ generation understood themselves to be migrant workers. He, like those before him, was living in poverty when he was tempted by an unscrupulous agent — or gato — who lived locally and promised work. Conceição was trafficked to the Amazon and, amid death threats and violence, set to work without pay, days off, decent food, safety gear or bearable living conditions.

Piauí, his home state, is one of the poorest in Brazil. Thirty-five percent of its residents live in households that earn less than one-quarter the minimum wage, which stands at 788 reals ($255) a month. Only two states are poorer, including the nearby Maranhão, also a recruitment hotbed. More than half the population lives without adequate sanitation, and 23 percent of adults are illiterate.

In Monsenhor Gil, a town of 10,000 people near the state capital, Teresina, just over 65 percent of residents live below the poverty threshold. At the cinderblock shack where Conceição grew up, the number 600 is daubed with yellow paint on the wall next to a rusting mailbox. Trees give shade to the scorched earth of the garden.

It was in this town that he met the agent, José Wilson, who also lived here, in 2004. A short, stubby man with a moustache, he talked a good talk and was convincing.

“They told us they had everything we needed at the farm, so to bring little,” Conceição said. “In truth, we thought we would be exploited and would work for little money. But we did not know the reality of how much we would suffer at their hands.”

Leaving his family for the first time, he was told to wait at the town’s corrugated iron bus stop early one morning with 14 other recruits. He took only three shirts, three pairs of shorts and a pair of shoes. There began his 800-mile, 60-hour journey to Santana do Araguaia, in Pará, along lawless and dangerous roads.

Clandestine buses roar down potholed single-lane highways through the shrub-strewn countryside at night to avoid the authorities. Sexual exploitation of children from the poor communities along the road by truck drivers is routine.

When Al Jazeera America retraced the route with Conceição in April, there was a stream of accidents — often involving donkeys, cows and pigs — on the road. The simple towns were marked by evangelical churches, cinderblock hotels and car repair workshops.

On the journey the workers talked of their families and slept. They stopped for a shot of cachaça at a roadside bar but no more. “We had heartache, as we did not want to leave our families, behind but we were so desperate for money,” Conceição said. He did not shower, since he could not afford the fee (about $1.60) at rundown truck stops.

“This movement of slaves has been going on since the expansion of capitalism into the Amazon about 40 years ago,” said Xavier Plassat, a French friar who leads the campaign against modern slavery for the Land Pastoral Commission in Brazil. “That created a tension over land here that has led to immense suffering.”

Conceição said the bus finally stopped on the roadside near Santana do Araguaia, in Pará state. The men were ordered onto a cattle truck with a cage section on the back — a design that still gives him flashbacks when he sees it.

“The promise was that we would go to a farm, but actually when we arrived, there was no farm,” he said. “We simply walked into the Amazon forest. When we were in the middle of the forest, we stopped, and we were ordered to put up a canopy.”

The men’s mission was to deforest that part of the Amazon to create a ranch and sell the timber. Many others who are enslaved there are put to work on livestock farms, with others forced to do dangerous work in coalmines.

Their leader was called José de Arimatéia, the name of the disciple who donated his tomb for Jesus’ burial after his crucifixion.

“He was a goat of a man, a nasty bit of work,” he said. “He was tall and always wore a hat. He kept a large machete by his side and always had a shotgun in his hand. He said that it was to get rid of the bad ones. I do not know what he meant by that. With him was José Wilson, who came with us from Monsenhor Gil, and a helper we called Barba.”

The 100-odd workers on the farm were woken at 4 a.m., when Barba would shout at them to get up. It would still be pitch black. There would be a long walk through the forest until work started at 5:30 a.m. It would not finish until 6 p.m. They never had a day off, and they had no idea how long they would be held before they were released. The food was white rice and uncooked black beans, with only dirty water to drink.

The men were left to fend for themselves in the middle of the jungle, sleeping in hammocks in the open under a leaking canopy.

“We spent most of the nights on our feet, since when it rained, the water would blow everywhere,” he said. “Most of our protection from the rain came from the trees above.”

The forest was dangerous, filled with jaguars, snakes, scorpions and hornets. “We were especially scared of the jararacussu, a deadly yellow and black viper with tiled scales,” he said. “One day we woke up, and there was one that was 3 meters long beneath the hammocks, and there was nothing we could do to scare it away.”

“We would keep our fire going all night because we thought the jaguars would be scared of it, but often in the morning we would see their footprints around our shack.”

The farm, Boca do Monte, appears to be among a recent trend of enterprises designed to involve too small an area to be picked up by the satellites the Brazilian government uses to track deforestation, which soared by 63 percent in the 12 months ending in January 2015, according to figures released by Brazil’s National Institute for Space Research. “This is a new pattern, and the government has struggled to respond to this,” said Ginny Baumann, an anti-slavery campaigner at the Freedom Fund.

Conceição said they were told that the deforested land would be used for cattle, but said he saw the wood being transported away for timber as well.

The workers were not paid and were told they had a debt to their masters they would have to repay. “It turned out the bosses had everything we needed — food, water, work clothes, tools, medicine — but their intention was to sell it to us,” he said.

The prices, too, were marked up, with a bag of rice costing the equivalent of $14.50 and a pack of bars of soap costing $4.80 — both five times the usual price in a shop. He said, “The boss would come and give orders to Barba. Then he would say to us, ‘Look, the patrão [boss] says you have to work even if you do not have the money to eat.’ He said that.”

When the men became ill, there was no proper medical treatment. A friend of Conceição’s injured himself cutting down a vine and was charged $16 for five stitches. The woman who did it had no training,” he said. “It was like she was sewing an animal.”

“The worst was when I saw a friend trembling, sick with a fever we thought was malaria,” he said. “He had no medicine, had no transportation, had nowhere to go. Malaria can kill, right? It is so difficult to see a sick friend and not be able to help him all night, not even be able to tell his family what is happening. That was hard.”

“In the evenings, we just kept talking and thinking, ‘How are we going to get away?’” he said. “Barba heard us and told us the bosses would find us and kill us.”

“I do not think I could have escaped. I had no money. I had left what I had at home. We could not have gotten away from there. There’s nowhere to go on foot. They took us to a place that you cannot walk, return, return on foot at all,” Conceição said.

The hardest thing for him was missing his relatives.

“Every single day, I had a yearning for my family,” he said. “When we stopped work, we would lie down and keep talking. On weekends I would imagine being back home, where they would be having a forró dance or be in the bar playing pool. But where we were, there was nothing — only sleeping and working.”

Then after three months, the men were suddenly released and put on a bus to Monsenhor Gil. “In those three months I did not receive a single cent,” he said.

The decision to release the workers came in the aftermath of a raid by inspectors from Brazil’s Ministry of Labor on a neighboring farm, in which 78 slaves were rescued. Conceição was given $77 to cover his trip home, but unlike the slaves rescued by the government, does not have a right to claim compensation. The owner of the raided farm was not arrested but was eventually ordered to pay $257 to $322 to each worker after a civil case brought by the Land Pastoral Commission.

“Getting home, it was a joy to see my family,” Conceição said. “My main fear was that I would die somewhere out in the forest without ever speaking to them again.”

“But I arrived home without money. My parents cried and asked me not to leave again. My sister gave me a crucifix to wear every time I travel to keep me safe.”

He is lucky because he never had to return to slavery, instead joining a cooperative of former slaves who work on their own land. But many others, even if they are rescued by federal inspectors, feel they have no choice but to return to the slavery road because of their financially desperate situation, said Plassat.

“I had terrible nightmares. I have no way to forget what happened,” Conceição said. “Still in our city people still migrate again and again to all of these places.

“They simply feel they have no choice.”

(Photography by Mario Tama)