Nabta Playa, an archaeological site in southern Egypt, was discovered in 1974. It is believed to have been a ritual center for a civilization that existed from 6400 to 3400 BC. Unlike other sites, Nabta Playa was purely ceremonial and featured strange structures, such as a mini Stonehenge. The alignment of the structures with the Orion constellation has puzzled researchers for over 30 years, indicating a sophisticated understanding of physics by the ancient builders.