The Strange Eye of Mauritania
Surrounded by the vast Sahara Desert is a cylindrical natural structure eerily shaped like an eye.
Visible from outer-space, the Eye of Africa (officially called the Richat Structure) , which spans approximately 48 km looks like a gigantic spiral carved deep into the Earth.
The spiral was spotted in central Oudane, Mauritania by astronauts. Scientists thought at first that it might have been created from a meteorite that hit Earth. Scientists also believe that the eye is actually caused by erosion.
According to Amusing Planet the circles that make up the eye are alternating layers of sedimentary, metamorphic and igneous rocks pushed up into a geologic dome.
Some claim that there is actually a hotel located in the middle of the eye. Such claims have been made on several websites that discuss the odd phenomenon. However according to NASA images, the hotel is not much more than a few wooden huts situated in the center of the spiral.