At the heart of California's Death Valley National Park is dry lake Racetrack Playa. It was born here and continues to be one of the most amazing mysteries of our planet - the mysterious moving stones.
Nobody has ever seen, as the stones move. But the fact that pieces of rock move, no one in doubt as they leave a trail upon the dry clay soil. It is noticed that the stones move every two or three years. It is also noteworthy that the cobbles with rough rectangular outlines of moving in a straight line, as evidenced by their track laid, and those who have smoothed corners - move along meandering path zigzags. Despite the research, geologists have reached an impasse. Put forward many theories, but none of them has not been confirmed. Found only that the stones do not move on dry ground, and the mud. During the rainy season in the lake there is a certain amount of water and at the bottom is formed soft and slippery layer of silt. But that's what makes them "crawl", still remains a mystery.