Khyargas Lake is a vast saline lake in western Mongolia, located in Uvs Province. Its size ranks it among the 4 largest lakes in the country, measuring 75 km long by 31 km wide. Like a inland sea, its average depth reaches 50 meters.

It is notably fed by the smaller, non-saline Airag Lake at its southern edge.

Khyargas Lake is part of an ecoregion designated by the World Wildlife Fund (WWF). It belongs to the "Great Lakes Basin Desert Steppe," an enclosed depression nestled between the varied peaks of the Altai and Khangai ranges. Numerous lakes dot this region, including Uvs, Khyargas, Khar-Us, and Airag.

This area has been recognized as a nature reserve since 2000, and stands as an example of faunal diversity.

One of the principal activities around the lake is observing migratory birds that pause here to rest, or fishing for Altai herring, Nokhoi fish, and pike.

Other pursuits await visitors meeting nomadic families: horseback riding or camel trekking, and playing traditional local games such as Shagai, the bone-casting game emblematic of Mongolian nomadic culture.