The Richat Structure: the 25 mile wide ‘Eye of the Sahara’ Deep in Mauritania’s Sahara Desert, this enormous geological formation creates a striking bullseye p

The Richat Structure: the 25 mile wide ‘Eye of the Sahara’ Deep in Mauritania’s Sahara Desert, this enormous geological formation creates a striking bullseye pattern visible from space. Its unusual shape even made it a useful landmark for astronauts in orbit