If you are visiting Mauritania, do not miss the opportunity to visit Richat Structure, or better known as The Eye of the Sahara. It is a set of concentric circles, the widest of which measures about 40 kilometers. This is an eroded dome created by the uplift of the ground under the influence of incoming magma from the depths of the Earth's crust. Astronauts have taken photographs of this geological phenomenon, which reveals the beauty that can be seen from Earth's orbit. You will surely be sorry that you did not visit this locality on Earth if you are already in relative proximity.