The Vault was not the first super-human detainment facility to appear in comic books. Marvel had shown their characters detained in various penitentiaries (usually alongside regular criminals) prior to "Avengers Annual" #15, most often at "Ryker's Island" (a fictionalized Rikers Island). Also, while DC Comics' more well-known Arkham Asylum predates the Vault by over twelve years, Arkham is technically a psychiatric hospital, not a prison. There is also Takron-Galtos, a prison planet which incarcerated many of the Legion of Super-Heroes' villains which first appeared in "Adventure Comics" #359 (August 1967).