
The Senegambian stone circles are megaliths found in Gambia north of Janjanbureh and in central Senegal. The megaliths found in Senegal and Gambia are sometimes divided into four large sites: Sine Ngayene and Wanar in Senegal, and Wassu and Kerbatch in the Central River Region in Gambia. Researchers are not certain when these monuments were built, but the generally accepted range is between the third century B.C. and the sixteenth century A.D. Archaeologists have also found pottery sherds, human burials, and some grave goods and metals. The monuments consist of what were originally upright blocks or pillars (some have collapsed), made of mostly laterite with smooth surfaces.
The construction of the stone monuments shows evidence of a prosperous and organised society based on the amount of labour required to build such structures. The builders of these megaliths are unknown, but some believe that the Serer people are the builders. This hypothesis comes from the fact that the Serer still use funerary houses like those found at Wanar
Here are some maps, also a few nice looking sources:
https://journals.openedition.org/aaa/1033 In French with very detailed maps
https://www.researchgate.net/publication/328098176_Senegambian_megaliths_as_world_cultural_heritage/figures?lo=1 And this paper
Yes indeed
I vaguely remember hearing of these before. I think they are nicknamed the "African Stonehenge."