Tonle Sap, the largest freshwater lake in Southeast Asia, was made a UNESCO biosphere in the late 1990s. The area is home to many ethnic Vietnamese and numerous Cham communities, living in floating villages around the lake. People living on or around the Tonle Sap subsist on the abundance of fish that the lake produces. During the fall season, The Water Festival is held to celebrate the reversal of the waters back into the Mekong. This popular celebration offers visitors the opportunity to sample the best of local fare as well as witness the famous Tonle Sap boat races.