Cambodia’s huge Tonle Sap Lake sits only 15 kilometers south from Siem Reap. It is the largest fresh water lake in SE Asia and is an ecological hot spot that was designated as a UNESCO biosphere in 1997. The Tonle Sap is unusual for two reasons, its flow changes direction twice a year and the portion that forms the lake expands and shrinks dramatically with the seasons. The engine of this massive lake is the Mekong River which becomes bloated with snow melt and the run off of the monsoon rains. The wet season inflow expands the area of the lake by more than five-fold inundating the surrounding flood plain and supporting an extraordinarily rich and diverse ecosystem
