El Salvador’s Cecot mega-prison was notorious long before the Trump administration’s recent decision to deport hundreds of alleged Venezuelan gang members there.

Here's what to know about the mega-prison in El Salvador where hundreds of immigrants were transferred after President Trump signed a wartime declaration - The Alien Enemies Act of 1798 - last used during World War II to target Venezuelan gang members.

Prisoners spend 23.5 hours a day locked in their cells, with a brief, 30-minute window for exercise or religious activities in a central hallway.