Mara Salvatrucha.

In 2013, photographer Adam Hinton from London managed to get inside the institution, which was originally built to accommodate 800 inmates and is now the nearly 2,500 members of the Mara Salvatrucha. Mara Salvatrucha, which means "Salvadoran gang stray ants" - a well-organized international criminal groups; one of the most violent, and many fast-growing street gangs of Central and North America.

 
It deals with many types of criminal business, including trafficking in drugs, arms and human beings; robbery, racketeering, contract killings, kidnappings for ransom, pimping, car theft, money laundering and fraud.