NABTA PLAYA: THE WORLD'S FIRST ASTRONOMICAL SITE WAS BUILT IN AFRICA AND IS OLDER THAN STONEHENGE THIS 7,000-YEAR-OLD STONE CIRCLE TRACKED THE SUMMER SOLSTICE AND THE ARRIVAL OF THE ANNUAL MONSOON SEASON. IT'S ALSO THE OLDEST KNOWN ASTRONOMICAL SITE ON EARTH.

https://astronomy.com/news/2020/06/nabta-playa-the-worlds-first-astronomical-site-was-built-in-africa-and-is-older-than-stonehenge