California's Death Valley , located in the Mohave Desert in the Southwestern region of America, is well-known for its extreme temperatures, varied altitude that ranges from 282ft. below sea level to 11,000ft above, and its beautiful rugged terrain.
What is not as well known however, is the fact, that it is also home to one of nature's biggest mysteries - Rolling or dancing stones!
And, we not talking tiny pebbles - but big boulders that weigh as much as 500lbs and move several hundred yards at a time, in a straight or zigzag pattern, leaving behind deep tracks on the desert sand.
Since the phenomenon occurs in Racetrack Playa, one of flattest areas of the valley, the rolling is not caused by a slope, nor, is it caused due to the rocks sliding when wet, a theory that was tested in the 1950's.
The most plausible theory put forward so far, has come from Professor Reed and his team of scientists from Hampshire College in Massachusetts, who researched the phenomenon for over a decade.
They believe that the below freezing nightly temperatures of Racetrack Playa turn the surface water to ice. When accompanied by the right amount of wind, the thin ice acts as a sledge, helping the rocks roll across the sand. Since the ice sheets are thin, they often break up while the rocks are rolling, explaining the willy-nilly routes of the rocks.
Of course, there are some who believe that the rocks are being dragged around by Park Rangers and others who are convinced that this is the work of Unidentified Flying Objects (UFO's)
However, nobody knows for sure - Because while the 'dancing' rocks of Death Valley have been observed for over a century, nobody has actually seen them roll!
What theory do you believe is true? Be sure to let us know by adding your comments below!