Richat Structure
The Richat Structure, which is commonly referred to as the “Eye of the Sahara,” is a prominent circular feature located in the Sahara region near Ouadane, west-central Mauritania.
This structure was initially interpreted as an asteroid impact structure due to its high degree of circularity, but geologists have ruled out this theory, referring to the whole formation as a highly symmetrical and deeply eroded geologic dome.
No evidence has been found to suggest shock metamorphism or any hypervelocity extraterrestrial impact. Studies of its origin are still ongoing.