The Senegambian stone circles (Cercles mégalithiques de Sénégambie) or the Wassu stone circles are groups of megalithic stone circles that lie in The Gambia north of Janjanbureh and in central Senegal. Spread across a region , they are sometimes divided into the Wassu (Gambian) and Sine-Saloum (Senegalese) circles, but this is purely a national division.
Containing over 1000 stone circles and tumuli spread across an area long and wide, the Senegambian stone circles are the largest concentration of stone circles seen anywhere in the world and an extensive sacred landscape that was used for more than 1500 years. As a result, the sites were inscribed on the UNESCO World Heritage List in 2006.
The stone circles and other 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. Among these four main areas, there are approximately 29,000 stones, 17,000 monuments, and 2,000 individual sites. The monuments consist of what were originally upright blocks or pillars (some have collapsed), mostly made of laterite with smooth surfaces. The monoliths are found in circles, double circles, isolated or standing apart from circles (usually to the east) in rows or individually. These stones that are found standing apart outside the circles are called frontal stones. When there are frontal stones in two parallel, connected rows, they are called lyre-stones.
Researchers are not certain when these monuments were built, but the generally accepted range is between the 23rd century B.C. and the 16th century AD. Burial mounds near the Wassu complex have been dated to AD 927–1305, although it is not clear whether the burial mounds were constructed before or after the stone circles. Archaeologists have also found pottery shards, human burials, and some grave goods and metals around the megalithic circles. A small collection of these can be found in the British Museum's study collection that was donated by the colonial administrator Sir Richmond Palmer.