Arkham Asylum

Arkham Asylum is a prison for the criminally insane located in Gotham City, United States of America.

History
Most of Batman's enemies are imprisoned in Arkham.

Current inhabitants

 * The Joker
 * The Riddler
 * Two-Face

Season 1

 * "Dick Grayson" (fake reality)

Behind the scenes

 * In the DC comics, Arkham Asylum is a mental institution for the criminally insane located in Gotham City.