Tartarus

Tartarus (タルタロス) is a location far away from the civilization, where Villains are being imprisoned to interrogate them under the highest security standards possible.

Description
The High-security prison appears to be located on an island, surrounded by giant walls. The only access to the prison is a bridge. The entrance is guarded by two or more guards, which will check every vehicle that wants to get into the prison. Sensors are continuously checking the vital functions of the prisoners, reacting even to the slightest sign of unusual behaviour or the attempt to activate a quirk.

History
Not much is known about the prison yet.

Prisoners
The prisoners are criminals for whom the death penalty is not enough. They are being kept underground, watched by a great amount of sensors and guards. For a certain time limit, the villains can be visited.
 * Hero Killer: Stain
 * All For One

Trivia

 * Tartarus, in Greek Mythology, is a Dungeon in the Underworld where the worst sinners are forever kept to be tortured for their evil deeds.