The Site is located along the south-eastern edge of the Tonle Sap Great Lake, and mainly comprises seasonally flooded freshwater swamp forests. Along the Stung Sen River, there are gallery forests, low-stature shrub land, inundated and submerged trees, and extensive mats of herbaceous and aquatic vegetation which provide habitat for a variety of species. The vegetation of Stung Sen is strongly influenced by the exchange of water between the Mekong River, the Stung Sen River and the Great Lake, and the area is subject to an annual flooding cycle that makes it extremely fertile. The Site is an important spawning ground for several fish species such as Jullien’s golden carp (Probarbus jullieni) and small scale mud carp (Cirrhinus microlepis), a migratory pathway and feeding ground for waterbirds, and an important habitat for mammals. It is regionally important for supporting a number of globally threatened species such as the critically endangered Mekong giant carp (Catlocarpio siamensis); the endangered yellow-headed temple turtle (Heosemys annandalii) and Indochinese silvered langur (Trachypithecus germaini); and the vulnerable lesser adjutant (Leptoptilos javanicus) and smooth-coated otter (Lutrogale perspicillata).