Arkham Asylum is a mental health facility in Batman vs. Teenage Mutant Ninja Turtles, located in or near Gotham City. Its inmates include criminally insane and dangerous individuals such as the Joker, Harley Quinn, Poison Ivy, Mr. Freeze, Two-Face and Scarecrow, who are kept on the premises more to imprison them than to treat them.
Shortly after the Ninja Turtles arrived in Gotham, Ra's al Ghul and Shredder infiltrated the facility and killed the entire security staff. Upon being released, Joker freed the other inmates and took the remaining staff hostage. After being alerted to the break-out, Batman, Robin, Batgirl and the Turtles came to Arkham in order to deal with the newly-mutated inmates.
The already decrepit condition of the facility was made worse by the battles that took place with the various villains, with large holes being knocked in the walls and floors.
Among the rooms seen in Arkham are:
- A large lobby that serves as the main entryway to the asylum.
- A large kitchen.
- A small gymnasium with a weight bench and multiple punching bags.
- A boiler room in the lower levels.
- A large upper-level room filled with transparent cells, in which the most dangerous inmates were previously kept.
- A security surveillance room.
- A large auditorium-like room with rows of seats and a high balcony.