From orbit it looks like a 40-kilometer bullseye carved into the Sahara, so perfect it tricks your brain into thinking it must be artificial. Astronauts use it to orient themselves, internet sleuths swear it's the lost city of Atlantis, and for decades the world's best geologists were certain a meteorite made it.

This episode unpacks the true story of Mauritania's Richat Structure, the so-called Eye of Africa. We trace how the meteorite theory collapsed, how a subterranean magma dome actually built the rings, and how that geology turned the site into a prehistoric oasis and human toolmaking hub before debunking the Atlantis myth entirely.

• Why the early meteorite theory fell apart after a mineral first identified as coesite turned out to be ordinary barite
• How a Cretaceous-era magma dome pushed up sedimentary layers that d ...