DC Universe: After the Fall
City: Gotham City
Arkham Asylum was built in 1892 by psychiatric physician Jeremiah Arkham in response to a growing number of criminally insane patients coming to the hospital where he worked. The Asylum was his life’s work, and was to be a place where the criminally insane of Gotham City would be kept isolated from the general populace while recieving the specialized care that they needed to recover from their illnesses. Jeremiah Arkham spared no expense in constructing his facility, filling it with containment cells, treatment facilities, and security measures to ensure the safety of those within and without. To add a second layer of protection, the entire building was built on an island just outside the waters of Gotham Harbor, too far from land for anyone to be able to swim.
Over the years, Arkham Asylum housed the worst of the worst of Gotham’s mad criminal underworld. Housing some of the most depraved psychopaths in Gotham’s history, the Asylum’s security levels were kept modern and properly upgraded throughout the years to compensate for the increasingly violent and dangerous of Gotham’s populace. However, the ruthless security measures that the Asylum took to keep its inmates under lockdown were often viewed as inhumane, but the facility only really came under fire after an incident that proved deadly during the Brainiac war.
As Metropolis was under siege by Brainiac, The Joker staged a mass breakout and hostile takeover of the Asylum. Along with Harley Quinn, Poison Ivy, Victor Zsasz, Scarecrow, Killer Croc, Bane and the Riddler, Joker seized complete control of the Asylum with Batman locked inside. This was after Blackgate Prison had been the target of an arson and its inmates had been temporarily transferred to Arkham while the prison was under repairs. The inmates overwhelmed the guards and killed many of them while the assembled supervillains tried to hunt down Batman and kill him within the Asylum. While Joker’s plans eventually failed, the people of Gotham City felt that the facility was no longer fit to serve as a safehouse for the criminally insane. By the end of that year, Arkham Asylum was shut down and the island quarantined permanently.
Since then, however, the Joker returned to the island and established the Clown Gang‘s new base of operations in the ruins of the old Asylum. As it technically lies outside of Gotham City’s borders, the city’s police force is powerless to do anything without federal support which the government has been reluctant to give, giving preference to the reconstruction of New Metropolis. As such, the Joker has been able to rebuild the asylum into a fortress and madhouse without any interference from official forces, and The Red Hood has proven unable to penetrate the asylum’s defenses… so far.