In El Salvador, gang members will be housed in a new, large prison complex.
On Wednesday, President Nayib Bukele presented the already completed plants during a tour in a video that was broadcast nationwide on television in the Central American country.
Up to 40,000 prisoners are to be locked up there from an as yet unspecified date.
Conservative Bukele wrote on Twitter that the detention facility in Tecoluca, around 75 kilometers south-east of the capital San Salvador, is an essential tool for completely winning the fight against violent gangs.
According to the government, the prison occupies a total area of 165 hectares in the center of the country.
Around 850 soldiers and police officers are to monitor it.
A state of emergency applies in El Salvador
The state of emergency has been in force in the country with six million inhabitants for almost a year.
A number of fundamental rights have been restricted.
The government wants to curb the violence of the criminal gangs.
Since then, more than 62,000 suspected gang members have been arrested, and the murder rate has recently fallen significantly.
However, human rights activists speak of arbitrary arrests.
With a prison rate of 605 people per 100,000 people, El Salvador already has more prisoners than any other country, according to the World Prison Brief database.
Almost 40,000 people are already in prison.