Ischigualasto, meaning "the place where you put the moon" is a remote valley in Argentina. It is studded with geological formations left by wind erosion, amazing standing stones and boulders that are so rounded they look like enormous marbles. The valley's once-fertile ground is now arid and contains so many plant and animal fossils that paleontologists come from all over the world to study them. Link
(Image credit: Flickr user Aylwin Lo)