Located about 25 minutes drive from Siem Reap downtown, the Tonle Sap Lake is the biggest natural attraction in Cambodia. A boat trip to explore Tonle Sap floating villages is its greatest appeal.
The Great Lake of Tonle Sap is the largest freshwater lake in South East Asia. It is a natural wonder of Cambodia, one of the unique geographical wonders of the world, and an ecological hot spot that was designated as a UNESCO biosphere in 1997. It is located at the central part of Cambodia and surrounded by five provinces: Kampong Chang, Pursat, Battambang, Siem Reap, Kampong Thom.
The lake is linked to the Mekong River by the Tonle Sap River. From November until June the lake flows into the Mekong. However, each year during the rainy season (mid June- late October) the Mekong River is inundated with rain waters. Its lower delta becomes flooded and cannot flow into the sea quickly enough to eliminate all the excess water. This causes the Mekong River to rise enough to reverse the flow of the Tonle Sap River causing it to flow back into the lake. The lake expands from 2,500 km2 to more than 16,000 km2 (160 Km long, 100 Km wide, 9m deep) creating an enormous wetland area. This wetland area supports a tremendous amount of biodiversity including plants, reptiles, mammals, birds and other animals. Many of these are known to be rare or endangered. These wetlands are also an important breeding area for fish from the lake and Mekong River.
The pulsing system with the large floodplain, rich biodiversity, and high annual sediment and nutrient fluxes from Mekong makes the Tonlé Sap one of the most productive inland fisheries in the world. Its floodplain is also a habitat for many species of birds, mammals, and reptiles found around the lake during migration.
Tonle Sap Lake is home to around 160 floating villages where you can see floating houses, restaurants, churches, billiards, souvenir shops, a crocodile farm and even pigs and dogs "floating"! Boat tours are widely available, departing from the Chong Khneas boat docks all day long. Tickets are reasonably cheap, but it is unsafe if going farther from the shore as the water becomes deeper.
The best time to visit Tonle Sap Lake is between March and April (wet season) as the lake narrows during the dry season.