Located in western Cambodia, Tonle Sap Lake is the largest freshwater lake in Southeast Asia. It stretches across nine provinces of Cambodia and connects to the Mekong River via the Tonle Sap River.

The Tonle Sap River, which links the lake to the Mekong, is the only river in the world that changes its flow direction with the seasons.

During Cambodia’s rainy season, the water level of the Mekong River rises above that of Tonle Sap Lake, causing water from the Mekong to flow into the lake via the Tonle Sap River. When the rainy season ends and the dry season begins, the Mekong’s water level drops below that of the lake, and the lake water then flows back into the Mekong through the same river.

 

 

In this way, Tonle Sap Lake serves as a natural reservoir for the Mekong River.

Because of this unique hydrological phenomenon, the lake’s surface area can vary several times in size between seasons, earning it the nickname “the beating heart of Cambodia”.

This unique geographical transformation greatly impacts agriculture along the lake’s shores. A large area of land surrounding Tonle Sap shifts annually between farmland and lake, with local agricultural activities alternating between farming and fishing depending on the season.

 

 

During the rainy season, the expanded lake area, along with organic matter brought by the river and the plants and animals submerged beneath, creates an excellent environment for fish to thrive. In the dry season, as farmland re-emerges, the soil—enriched by the abundant organic deposits accumulated over the rainy season—becomes fertile and ideal for rice cultivation. Tonle Sap Lake thus enables the communities along its shores to enjoy bountiful harvests year-round.

When visiting Tonle Sap Lake, besides witnessing the seasonal changes of the lake’s scenery, you can also see unique waterborne dwellings adapted to local conditions. These structures showcase the water-based living wisdom of the communities along the lake’s shores.

 

 

One type of dwelling closely connected to the lake is the houseboat. It rests on floating platforms or wooden frames that provide relative stability and rise or fall with the changing water levels. When the water is high, the houseboat floats on the surface; when the water is low, it settles closer to the lakebed. This design allows the structure to adapt maximally to the fluctuating water environment. People live on these houseboats, and they can even grow vegetables and raise fish on them. All daily life activities are carried out on the houseboats and the boats that come and go on the water.

Another type is the stilt house built along the lake’s edges, designed to adapt to the rising and falling water levels. These houses are elevated on tall stilts, so when the lake water rises, it only covers the stilts without affecting the main structure of the house.

Step into Tonlé Sap Lake to experience the wonders of nature, discover unique ways of life, and listen to the rich cultural stories hidden within the waters.