Mario's castle

Mario's Castle is a castle that is owned by the legendary hero Mario. Wario steals this castle through the events of Super Mario Land, and Super Mario Land 2: Six Golden Coins. Wario transforms the castle into a huge death trap wih tons of obstacles.

Inside are metal spiked balls, Piranha Plant statues that spit fire, and Giant Gloved Fists (Wario's gloves, to be exact) that try to punch Mario if he comes too close. Extremely odd creatures live here; one of them (actually a species) is a type of bouncing ball with Wario's face on it. If Mario beats Wario, the spell is broken and the castle turns white instead of black (and its "M," turned upside down to resemble a "W," is moved back into its correct position).