Looks like El Salvador's Special Prison for Gang Members
From what I heard, especially for gang members only, about 15,000 of them or so
https://en.wikipedia.org/wiki/Terrorism_Confinement_Center
They're at the prosecutor's opening statement currently
Law & Crime has a live stream (there's others if one searches utube)
https://youtube.com/watch?v=JcDusZLlVEc