Encyclopedia Barsoomia Wiki
The information in this article comes from Disneys John Carter and is not written by Edgar Rice Burroughs.

Gothan's Citadel is a mysterious structure upon Barsoom, and it is where the Warhoon Gothan spent his final days. The area it is situated in is painted to appear as a deep gorge when viewed from above (presumably by Gothan who has made a hobby of painting) and the citadel itself is camouflaged against the mountains. The stairs at the base of the citadel are a completely nonsensical labyrinth, it seems as though the only option is to climb the tower and ignore the steps entirely.