The operators of the small site (which is about 150 feet (46 m) in diameter) claim at that location the laws of physics and gravity do not apply and provide a number of demonstrations in support of these claims, where water seems to flow upwards, people seem to be standing in slanted positions, etc.
The Mystery Spot is a gravity hill, a 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.
Around 1943, a lumber company was attempting to sell the land that is currently the Mystery Spot parking lot. When it was sold, however, the lumber company forced the buyer to also buy two hills to the north and south. When a few men working for the buyer traveled up one of the hills, they immediately became exhausted and could hardly pull out a compass. The previous plans to build summer homes and cabins were abandoned and instead, the Mystery Spot attraction was built.
- Shimamura, A. P. & Prinzmetal, W. (November 1999). "The Mystery Spot Illusion and its Relation to Other Visual Illusions" (PDF). Psychological Science 10 (6): 501–507. doi:10.1111/1467-9280.00196.
- Mystery Spot official website (California)
- Video Tour of the Mystery Spot (California)
- Mystery Spot explained (SandlotScience.com)—this site contains explanation about how Mystery Spots work, including a list of mystery spots
- Further article explaining the illusion (Berkeley.edu)