The Richat Structure, also known as the Eye of the Sahara, is a prominent circular feature in the Sahara desert near Mauritania. This structure is a deeply eroded, slightly elliptical, 40 km in diameter dome. The sedimentary rock exposed in this dome ranges in age from Late Proterozoic within the center of the dome to Ordovician sandstone around its edges. Some scientists suggest there is evidence that they eye is remnants of a geologic dome formed approximately 100 million years ago. #RichatStr