The Osun-Osogbo Sacred Grove stretches for about 75 hectares along the banks of the Osun River on the northern edge of the city. It is one of the last examples of a type of sacred grove that once existed across Yorubaland, and its designation as a UNESCO World Heritage Site in 2005 acknowledged both its ecological and cultural value. The forest contains the river goddess Osun's principal sanctuary, along with dozens of shrines, sculptures, and works of art accumulated over centuries of Yoruba religious practice.
The grove is most spectacular during the Osun-Osogbo Festival, held each August. For two weeks, priests and worshippers from across the Yoruba world converge on the grove. The climax is a procession to the river carrying the arugba — a young virgin bearing a sacred calabash on her head — watched by crowds of tens of thousands. Outside festival time, the grove is quiet and deeply atmospheric, the river running brown and slow through dense forest.