Koopacropolis

The Koopacropolis is a platform situated at the top of a large hill, it was also used as the hideout of King Koopa in The Super Mario Bros. Super Show! episode "The Fire of Hercufleas". Not much of the Koopacropolis is actually seen, though from little of it was seen, it seems to be almost nothing more than a fortress on a mountain, the inside of which, was fairly plain in appearance. After he was defeated, King Koopa and his minions abandoned the Koopacropolis.

Trivia

 * The name of this episode is a pun of acropolis, which means high city in Greece.