Located in one of the flattest places on the face of this planet are the strange and unexplained Sailing Stones of Racetrack Playa, Death Valley, California. Once a year the "Playa" or flat desert pan experiences short winter rains and becomes slippery as the hexagonal desert floor turns back to mud. During this time the boulders and rocks move leaving clearly visible tracks behind them.
Racetrack Playa in Death Valley California: Scattered about the desert are large rocks with mysterious trails left behind them. The trails show that these rocks have rolled and zig-zagged across the ground, sometimes for as long as 860 feet. Yet no one has ever seen the stones actually move. The trails last for years before fading, so it is almost impossible to predict when the stones will move or how fast they move.