The Eye of the Sahara

The Richat Structure (also known as the Eye of the Sahara or Eye of Africa) is a natural anomaly in the midst of the Sahara Desert, in the Adrar region of Mauritania. It measures about 40km (25 mi) wide and is layered in circles of various igneous rocks caused from a magma eruption millions of years ago. Over time, it has eroded down significantly from the high winds and sands of the Sahara into a depressed, ringed formation.