Arkham Institute is a prison in which the criminal insane of Gotham are held
Inmates
- Joker
- Riddler
- Egghead
- Siren
- Shame
- Bookworm
- Chandell
- False Face
- Clayface
- King Tut
- Harley Quinn
- Scarecrow
- Killer Croc
- Mr. Freeze
- Killer Moth
- Solomon Grundy
and many more