Officially known as the Richat Structure, the Eye of the Sahara looks exactly like what its much more appropriate nickname describes. Located in the Mauritania branch of the Sahara, the eye is a 30-mile-wide collection of raised rocks that, for one reason or another, wound up in the shape of an eyeball. A grotesquely infected mummy eyeball, to be sure, but an eyeball nonetheless.
Google Earth via geology.rockbandit.net
"WHERE'S THE f*****g VISINE?"
It was initially thought to be a meteorite impact zone, but people soon realized that meteorites typically punch craters into the Earth, and don't just cut a bunch of doughnuts in the sand before launching themselves back into space. Then it was suggested that the ridges might have been formed by a volcanic eruption, but that theory proved to be equally full of wrongness once people realized that there aren't any volcanic rocks anywhere near the damn thing. Nowadays, the prevalent belief is that the Eye was formed by the gradual erosion of nearby rocks over the centuries, and they just happened to settle into the shape of an eye. While that may turn out to be true, it's important to note that all of these theories have overlooked the most obvious explanation: magic.