A convoy of trucks carrying tents, construction materials and portable toilets flows into a virtually abandoned airport in Florida’s picturesque Everglades, a Unesco World Heritage Site.

But they’re not helping build the region’s next big tourist attraction.

Instead they’re laying the foundations for a new migrant detention facility, dubbed “Alligator Alcatraz”.

The facility, in the middle of a Miami swamp, was proposed by state lawmakers to support US President Donald Trump’s deportation agenda.

“You don’t need to invest that much in the perimeter. If people get out, there’s not much waiting for them other than alligators and pythons,” explains the state’s attorney general, James Uthmeier, a Republican, in a video set to rock music and posted on social media.

The new detention centre is being built on the site of the Dade-Collier Training and Transition Airport, about 43 miles (70km) from central Miami, in the middle of the Everglades, an ecologically important subtropical wetland.

The airfield where the detention centre will be based is mainly a pilot training runway surrounded by vast swamps.

In the stifling summer heat rife with mosquitoes, we managed to advance only a few metres into the compound when, as expected, a guard in a lorry blocked our way.

We hear sounds coming from a small canal next to the compound. We wonder whether it’s fish, snakes, or the hundreds of alligators that roam the wetland.

Although the airstrip belongs to Miami-Dade County, the decision to turn it into a detention centre was made following a 2023 executive order by Republican Governor Ron DeSantis, invoking emergency powers to stem the flow of undocumented migrants.

The new centre, which according to authorities will have the capacity to accommodate around 1,000 detainees and will begin operations in July or August, is quickly becoming a controversial symbol of the Trump administration’s immigration policy.

Speaking at a press conference on Wednesday, DeSantis hinted that the Alligator Alcatraz being built in the middle of a swamp might not be the last.

“We’ll probably also do something similar up at Camp Blanding,” DeSantis said, referring to the former US Army training facility over 300 miles north.

He said a state official was “working on that” and would have a formal announcement “very, very quickly”.

As Trump orders immigration authorities to carry out “the single largest mass deportation programme in history”, human rights organisations say detention centres are becoming overcrowded.

Immigration and Customs Enforcement (ICE) has a record 59,000 detainees nationwide, 140% above its capacity, according to data obtained by CBS News.

Betty Osceola, a member of the Miccosukee Native American community, lives near the site and recently took part in a protest against the facility.

She suspects that rather than being a temporary site as authorities have stated, it will operate for months or even years.

“I have serious concerns about the environmental damage,” Ms Osceola tells us while we were talking next to a canal where an alligator was swimming.

She is also concerned about the living conditions that detainees may face in the new facility.

Those concerns are echoed by environmental organisations, such as Friends of the Everglades, and by human rights organisations in the U.S.

The American Civil Liberties Union (ACLU) of Florida told the BBC the proposed facility “is not just cruel and absurd. It underscores how our immigration system is increasingly being used to punish people rather than process them.”

Even ICE detention centres in populated areas, the ACLU said, “have well-documented histories of medical neglect, denial of legal access, and systemic mistreatment”.

BBC Mundo contacted the Florida attorney general’s office, but did not receive a response.

In the social media video, Uthmeier says the project is an “efficient” and “low-cost opportunity to build a temporary detention facility”.

With the “Alligator Alcatraz”, he says, there will be “nowhere to go, nowhere to hide”.

Expanding, adapting, or building new detention centres has been one of the Trump administration’s main challenges in accelerating deportations.

Homeland Security Secretary Kristi Noem said in a statement to the BBC that Florida will receive federal funds to establish the new detention centre.

“We are working at turbo speed on cost-effective and innovative ways to deliver on the American people’s mandate for mass deportations of criminal illegal aliens,” she added.

“We will expand facilities and bed space in just days, thanks to our partnership with Florida.”

Noem says that the facility will be funded by the Federal Emergency Management Agency (Fema), which is responsible for disaster co-ordination.

Daniella Levine Cava, the Democratic mayor of Miami-Dade County, which owns the airstrip land, says that she has requested information from state authorities.

The mayor “clearly laid out several concerns” regarding the proposed use of the airport, namely around funding and environmental impacts, her office said in a statement to the BBC.

While immigration raids have increased in cities like Los Angeles, the operations to detain migrants seem to be so far less widespread in Miami Dade County and South Florida.

Many undocumented Latinos prefer to stay at home because they are afraid of being arrested and sent to detention centres, according to testimonies gathered by BBC Mundo.

Follow the twists and turns of Trump’s second term with North America correspondent Anthony Zurcher’s weekly US Politics Unspun newsletter. Readers in the UK can sign up here. Those outside the UK can sign up here.