This is the Richat Structure, also known as Eye of the Sahara. This is a prominent circular feature in the Sahara desert located at the west-central Mauritania. Wikipedia describes this as 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. The sedimentary rocks comprising this structure dip outward at 10°–20°. Differential erosion of resistant layers of quartzite has created high-relief circular cuestas. Its center consists of a siliceous breccia covering an area that is at least 3 km in diameter.
One thing is only certain, God created this enigmatic structure that is clearly seen by astronauts in outer space. This is a characteristic of God's mystery and magnanimity. We don't have to explain everything that God created. We would only be awed and be amazed and be happy for all things beautiful and wonderful.
Photo Credit: space.io9.com