The Racetrack Playa is a large, utterly flat plain of dried mud in Death Valley's northwest section. The thing that makes people drive the 27 miles of bone-jarring washboard road to reach it is the spooky moving rocks. The rocks here move, leaving trails behind them that are sometimes quite long and convoluted. Nobody has ever seen the rocks actually move, and nobody is quite sure exactly how it happens, though theories abound. The most plausible theory is that when the Playa is wet, it becomes extremely slippery, enough so that the high winds in the area can push the rocks around.