One of the world's busiest migrant corridors runs from Central America through Mexico.

For decades, migrants from the northern triangle of that region — Honduras, El Salvador and Guatemala — have fled countries plagued by endemic levels of violence and crime in the hopes of crossing the Mexican border and eventually seeking asylum in the United States.

But migration experts say the profile of those using that route is rapidly changing.

With European borders tightening and increased anti-immigration anxiety in the United States, a rising number of migrants from as far away as Africa and Asia are turning to the Central American migrant corridor in the hopes of reaching a new promised land: Canada.

Tapachula, in the Chiapas region of Mexico, is a key transit hub on the Mexican-Guatemalan border. CBC News met dozens of migrants there, young men and women who fled their homes in Somalia, Ghana, Guinea-Bissau, Ethiopia, Eritrea, India, Bangladesh, Nepal and Haiti.

Many say they began their journeys — which take between three and five months and cost upwards of $20,000 US — with Canada in mind. Others changed their plans and want to reach Canada in fear of U.S. President Donald Trump's immigration policies.

All have faced extraordinary journeys to reach Tapachula — threatened by smugglers, robbed at gunpoint, trekking through jungles with little food or water.

Border crossing

A map showing the route many African migrants take - with the help of smugglers - to get to Canada. (CBC)

The majority of African and Asian migrants enter South America through Brazil or Bolivia, countries that in some cases they can enter without a visa.

They travel by boat, bus or foot through Peru, Ecuador, Colombia, Venezuela, Panama, Costa Rica, Nicaragua and Guatemala — countries that grant them temporary visas of 20 days to transit through the country — before reaching the Mexican border.

Almost none speak any Spanish. They are easy targets for violent smugglers and extortion by immigration agents along the well-trodden route.

Most say they met migrants of their country of origin in almost every country they crossed.

By the time they reach the Mexican border, they are often travelling in groups of between five and 20 people.

They cross into Mexico by raft at an informal but dangerous river crossing used to transit guns and drugs as well as people.

Whereas most Central American migrants pay approximately $1 US to cross, African and Asian migrants are charged nearly 10 times as much.

Latin America's biggest detention centre

Protests against overcrowding are a regular occurrence at the immigration centre in Tapachula, Latin America's largest. (Marc Robichaud/CBC)

The immigration centre in Tapachula is the largest in Latin America. Protests against overcrowding are a regular occurrence inside.

Many of the hundreds of thousands of Central American migrants who cross into Mexico are often detained here before being deported by bus back to their countries of origin. African and Asian migrants, whose countries do not have deportation agreements with Mexico, line up outside to apply for a temporary transit visa.

Last year, the immigration centre in Tapachula registered 442 African migrants in a single day.

Simanto, 25, Bangladesh

Simato, who didn't want to be photographed head on because he fears for his safety and the safety of his relatives, says his family in Bangladesh sold everything they had and gave him $4,000 US to make the trip to Bolivia and through the Central American corridor to the U.S. (Marc Robichaud/CBC)

Simanto arrived at the Tapachula detention centre on a hot Sunday afternoon with five fellow migrants from Bangladesh, India and Nepal.

A Hindu, Simanto fled his home after a spike in violent attacks against his country's long-persecuted minority group.

The 25-year-old says his family, which sells fish, sold everything they had and gave him $4,000 US to make the trip to Bolivia and up through the Central American corridor to the United States.

But Simanto, who wished not to show his face or use his last name because he fears for his safety and the safety of his family at home, says he doubts he will be granted asylum in the United States.

He says he is considering trying to reach Canada and may risk crossing illegally into the U.S. to do so. He owes that to his parents, he says, who gave up everything to help him leave Bangladesh.

Pierre Gracia, 21, Haiti

Pierre Gracia left Haiti with others who want to reach Canada, but they aren't sure how they will get there. (Marc Robichaud/CBC)

Many attempting to reach Canada through the Central American corridor are economic migrants.

Pierre Gracia, 21, left St. Marc, Haiti, with a group of nearly 20 country men and women. They say the immigration policies of U.S. President Donald Trump have scared them into remaining in Mexico for now rather than passing through to the U.S.

They aren't sure how they will reach Canada, but say it is their country of preference.

Mama Africa

Concepcion Gonzalez Ramirez runs a hostel in Tapachula and often provides migrants with small amounts of money to buy bread or coffee. (Marc Robichaud/CBC)

They call her Mama Africa.

Concepcion Gonzalez Ramirez runs a $3-a-night hostel just off of Tapachula's main strip that is known among the African migrants who pass through Mexico.

Many migrants stay here in groups, planning their next steps or waiting for friends who have been detained by immigration authorities before proceeding north.

Ramirez says she teaches the migrants who stay here about the local food and often provides them with small change to buy coffee and bread.

She says people often prey on the migrants, believing they have access to cash, but she lives with them and knows that they travel with only the clothes on their backs, often eating only one meal a day.

Rahma, Somalia

Women following the migrant corridor encounter further risks such as exploitation along the well-trodden route through South and Central America. (Marc Robichaud/CBC)

Women face additional risks along the migrant corridor, including sexual assault and exploitation.

Rahma, who wished not to show her face or use her last name because she fears for her safety and the safety of her family back home, says she fled Somalia after her husband was killed. Her uncle helped her secure a passport and connect with a smuggler who helped her reach Brazil.

Rahma spent six days in Tapachula's detention centre before being released. After several months travelling across South and Central America, she says she's too scared to enter Trump's United States.

Khadr, 31, Somalia

Khadr, who didn't want to show his face for fear it would endanger his safety, fled Mogadishu's civil war and is determined to reach Canada. (Marc Robichaud/CBC)

Khadr fled Mogadishu and that country's civil war.

The 31-year-old is staying in the Mama Africa hotel with nearly a dozen other Somalis, all of whom are on 20-day visas that run out in less than two weeks. They are unsure of what to do next.

Khadr, who also wished not to show his face or use his last name because he fears for his safety and the safety of his family back home, says the Canadian people and Prime Minister Justin Trudeau are welcoming of refugees, citing Canada's resettlement of Syrians.

He says he lost one of his toes while trekking through the Darien Gap, the wild jungle that connects Panama and Colombia. He knows Ghanaian refugees have also lost fingers and toes crossing the Canada-U.S. border in freezing temperatures, but he says nothing will stop him from reaching Canada.