Ghost House
Ghost Houses are large buildings where various Boos live. Since you can save your game every time you complete one of these in Super Mario World, you should go through them when you complete a hard level. There's 6 Ghost Houses in Dinosaur Land: 2 in Donut Plains, and 1 in the Vanilla Dome, Forest of Illusion, Chocolate Island, and Valley of Bowser.
It is followed by Big Boo's Haunt in Super Mario 64 and in Paper Mario. Bow's home, Boo's Mansion, is obviously a ghost house, and so is Creepy Steeple in Paper Mario: The Thousand Year Door.
On Sirena Beach in Super Mario Sunshine is Hotel Delfino, which is considered to be the ghost house of Super Mario Sunshine. Several of them are in New Super Mario Bros. and introduced more new ghost species.
