From the viewpoint of an environmental reclamation engineer, the sacred groves of the ancient world were a highly effective method of maintaining a healthy ecosystem and a clean water supply over the long term. Often located on the outskirts of a village, sacred groves typically featured shrines built along a serpentine river.
In Nigeria, a Yoruba legend recounts the voice of Osun the river goddess warning early settlers not to cut down her trees. The settlers heeded her warning and established the city of Osogbo on higher ground, while dedicating the forest to the river goddess. Today the Osun Sacred Grove is preserved together with 40 shrines along the snaky river.