Khar-Us Lake (, "Black-Aqua Lake", is a lake in western Mongolia in the Great Lakes Depression. It is the upper one in a system of the interconnected lakes: Khar-Us, Khar, Dörgön, Airag and Khyargas. The lake is located in Har Us Nuur National Park. Its area value (1,852 km2) includes the island Agbash (or Ak-Bashi, white head) area (274 km2), so the water surface area is 1,578 km2 only. Some sources are using different Khar-Us Lake Lake statistics values: Primary inflow is the Khovd River, which creates a large river delta. So called Genghis Khan's wall runs along the western shore of the Khar-Us Lake. It is possible to find it at the Google Map and Google Earth satellite maps 47.89139°N, 91.99361°W.