Researchers suspect the ancient stone circle Nabta Playa was used to determine the summer solstice, signaling the upcoming rainy season.
Nabta Playa located in the Egyptian desert may be the world’s oldest astronomical observatory. The desert is located in southern Egypt, about 280 km southwest of Aswan, and was once inhabited by the ancient Nubian people. The stone circle was built about 7,500 years ago, 2,000 years older than Stonehenge, according to Live Science.
Today, the main stone pillars of the building are located in a museum in Aswan to prevent vandalism. But originally, Nabta Playa consisted of dozens of vertical stone blocks, each more than a meter high, in the desert 100 km west of the Nile River. In addition to the stack of stones above the central tomb, many of the stones appear to have been arranged intentionally in a circular pattern, corresponding to the positions of certain stars. The 6 stone blocks inside the circle can serve rituals or mark important astronomical events. These stone blocks are surrounded by 29 stone pillars, forming a kind of primitive calendar.
Excavation of the central tomb in 2001 found no remains, only the complete skeleton of a cow. Along with other evidence, the discovery suggests that Nabta Playa was built by Stone Age people who depended on herding livestock among the seasonal lakes. The stone block in the circle may mark the Sun rising on the summer solstice, signaling that rain will help fill the lake. The three rocks in the center represent Orion’s belt and some of the rocks mark bright stars such as Arcturus, Sirius and Alpha Centauri.