Oubliette is a supermax prison complex operated by the United States of America. The prison is being used to contain the most dangerous villains in the world. The prison is the most secure in the world and is considered the hardest prison to escape from. The prison's existence is kept secret from the public's knowledge. The entire population of the prison is female because only females can use magic. The prison is situated in the desolate expanse of the Nördland Ice Shelf, approximately 300 miles south of the Antarctic Circle.