Fantastic Natural Phenomena‏ - Sailing Stones

The classical natural wonders are huge and hard to miss - vast canyons, giant mountains and the like. Many of the most fantastic natural phenomena, however, are also least easy to spot. Some are incredibly rare while others are located in hard-to-reach parts of the planet. From moving rocks to mammatus clouds and red tides to fire rainbows, here are seven of the most spectacular phenomenal wonders of the natural world.

The mysterious moving stones of the packed-mud desert of Death Valley have been a center of scientific controversy for decades. Rocks weighing up to hundreds of pounds have been known to move up to hundreds of yards at a time. Some scientists have proposed that a combination of strong winds and surface ice account for these movements. However, this theory does not explain evidence of different rocks starting side by side and moving at different rates and in disparate directions. Moreover, the physics calculations do not fully support this theory as wind speeds of hundreds of miles per hour would be needed to move some of the stones.