Luigi's Mansion (baseball stadium)
From the Super Mario Wiki, the Mario encyclopedia
Luigi's Mansion is a baseball field in Mario Super Sluggers. The stadium is located in a replica of the backyard of the mansion itself, and features gravestones located throughout an overgrown outfield. Coming within a certain range of the stone causes a generic ghost from the mansion to attack the player. The field can only be accessed by playing the game when it is night. It can be entered when the player purchases Luigi's Flashlight for 300 coins from the Mario Stadium shop. Thick grass grows in the outfield, making it difficult for the players to find the ball.
The stadium's minigame is called Ghost K. It involves the player throwing balls at colored ghosts in attempt to get the highest score.