Bowser's Castle (Mario Tennis Open)

Bowser's Castle is a tennis court in the game Mario Tennis Open for the Nintendo 3DS. It is a stone court built over a boiling lava landscape. Mechakoopas can be seen on the sidelines as spectators. A refereeing Toad is seen sitting in a cage outside the castle itself, where the normal referee's throne is. This court is where the Shell Cup takes place in Tournament mode. The music for this court is a cover version of Bowser's theme from Super Mario 64 and the Bowser Battle theme from Super Mario 3D Land.

In-game description
"Bowser's fiery court built on boiling magma."