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.

2) Columnar Basalt

Blue holes are giant and sudden drops in underwater elevation that get their name from the dark and foreboding blue tone they exhibit when viewed from above in relationship to surrounding waters. They can be hundreds of feet deep and while divers are able to explore some of them they are largely devoid of oxygen that would support sea life due to poor water circulation - leaving them eerily empty. Some blue holes, however, contain ancient fossil remains that have been discovered, preserved in their depths.

4) Red Tides

While many see these apparently perfect ice circles as worthy of conspiracy theorizing, scientists generally accept that they are formed by eddies in the water that spin a sizable piece of ice in a circular motion. As a result of this rotation, other pieces of ice and flotsam wear relatively evenly at the edges of the ice until it slowly forms into an essentially ideal circle. Ice circles have been seen with diameters of over 500 feet and can also at times be found in clusters and groups at different sizes as shown above.
 
6) Mammatus Clouds