Khar-Us Lake is a freshwater lake in the Great Lakes Depression of western Mongolia at an altitude of 1157 meters. The lake is one of four lakes in Mongolia with an area of ​​more than a thousand square kilometers. Although large, it is a very shallow lake with a maximum depth of 4.4 meters and an average depth of 2 meters.

The Khar Us Lake depression has tectonic origins, but due to prolonged drying, the shoreline has become more sloping, and reeds have grown densely along the shoreline.

 Khar Us Lake has an area of ​​1,153 square kilometers and its length is 72 kilometers, 26 kilometers wide.

 The lake was taken under State Protection in 1997, including Khar Lake and Durgun Lake. The area is home to 54 species of mammals, 268 species of birds, 455 species of grasses, 4 species of fish, 6 species of reptiles, and 131 species of insects.

 The Khovd and Buyant rivers, which originate in the Mongol Altai Mountains, supply about 2.2 km³ of water per year, and also confluence to the Khar-Us Lake via the 40 km long and 50-75 km wide Chono-Kharaikh River.

Islands of Khar Us lake:
There are more than 10 large and small islands in Khar-Us Lake, the largest of which is Agvash, an area of ​​274 km2, about 30 km long, and 272 m above sea level. It divides Khar-Us Lake into two unequal parts, north and south.