Cambodia’s Great Lake, the Boeung Tonle Sap (Tonle Sap Lake,) is the most prominent feature on the map of Cambodia – a huge dumbbell-shaped body of water stretching across the northwest section of the country. In the wet season, the Tonle Sap Lake is one of the largest freshwater lakes in Asia, swelling to an expansive 12,000 km2. During the dry half of the year the Lake shrinks to as small as 2500 km2, draining into the Tonle Sap River, which meanders southeast, eventually merging with the Mekong River at the ‘chaktomuk’ confluence of rivers opposite Phnom Penh. But during the wet season a unique hydrologic phenomenon causes the river to reverse direction, filling the lake instead of draining it. The engine of this phenomenon is the Mekong River, which becomes bloated with snow melt and runoff from the monsoon rains in the wet season. The swollen Mekong backs up into the Tonle Sap River at the point where the rivers meet at the ‘chaktomuk’ confluence, forcing the waters of the Tonle Sap River back upriver into the lake. The inflow expands the surface area of lake more than five-fold, inundating the surrounding forested floodplain and supporting an extraordinarily rich and diverse eco-system. More than 100 varieties of waterbirds including several threatened and endangered species, over 200 species of fish, as well as crocodiles, turtles, macaques, otter and other wildlife inhabit the inundated mangrove forests. The Lake is also an important commercial resource, providing more than half of the fish consumed in Cambodia. In harmony with the specialized ecosystems, the human occupations at the edges of the lake is similarly distinctive – floating villages, towering stilted houses, huge fish traps, and an economy and way of life deeply intertwined with the lake, the fish, the wildlife and the cycles of rising and falling waters.

Tonle Sap Exhibition in Siem Reap
The Exhibition on the Khmer Heritage is sponsored by Krousar Thmey. The current exhibition is dedicated to the Tonle Sap Lake and the people, culture and environment of the area. The displays are actually quite informative and include maps, photos, models of traditional houses, boats and fishing implements with written explanations in French, English and Khmer. The highlight of the exhibit is a working scale model of the Tonle Sap Lake. There are also exhibits on the work of Krousar Thmey.