The Racetrack Playa is a scenic dry lake feature with "sailing stones" that leave linear "racetrack" imprints.
It's located above the northwestern side of Death Valley, in Death Valley National Park, Inyo County, California,U.S..
The sailing stones are a geological phenomenon found in the Racetrack. The stones slowly move across the surface of the playa, leaving a track as they go, without human or animal intervention. The force behind their movement is not understood and is the subject of research. Racetrack stones only move every two or three years and most tracks develop over three or four years. Stones with rough bottoms leave straight striated tracks while those with smooth bottoms wander. Stones sometimes turn over, exposing another edge to the ground and leaving a different track in the stone's wake.
It still mystery to scientists and the nature is still playing with us..