The Mystery Spot is a gravity hill, tilt-induced visual illusion. The illusion experienced by visitors results from the oddly tilted environment as well as standing on a tilted floor. Inside the tilted room of the Mystery Spot, misperceptions of the height and orientation of objects occur. Even when people are standing outside on a level ground, the slant of the building in the background causes misperceptions as humans judge the height of people using the slant of the roof rather than the true horizon.