Banishment Zone

The Banishment Zone is a zone mentioned in The Adventures of Super Mario Bros. 3, where King Koopa was sent before the events of the cartoon. However, King Koopa escapes the Banishment Zone and returns to the Mushroom Kingdom again.

It is unknown how Mario, Luigi, Princess Toadstool and Toad sent King Koopa to the Banishment Zone. Supposedly, it was after the events of The Super Mario Bros. Super Show. Nothing else is known about this mysterious zone.