The Battle Dome
From the Super Mario Wiki
The Battle Dome is a field in Super Mario Strikers which later reappears in Mario Strikers Charged. The Battle Dome is located in Bowser's Castle. The capacity is 68,000 (the largest capacity of any of the Mario Strikers fields) and is made out of concrete. It is the Super Star Cup's special field. The design, structure, and shape of the goal changed between Super Mario Strikers and Mario Strikers Charged.