Achit Lake is a freshwater lake located on the border of Uvs and Bayan-Ölgii provinces. The lake's shores are flat, and its northwest and northeast areas are marshy. It collects water from many rivers originating in the major branches of the Mongol Altai Range, including the Siiikhlem and Turgen ranges, as well as rivers like the Tsagaan Nuur, Khatuu, Bukhmurun, and Uliastai rivers and discharges its excess water into the Khovd River .The area around the lake is predominantly inhabited by people of the Durvud and Kazakh ethnic groups.
The lake is home to rare birds listed in Mongolia's "Red Book," including the black stork, whooper swan, steppe goose, greylag goose, white-tailed eagle, pheasant, great bustard, little bustard, Asian dowitcher, and Relict gull.
The lake's waters contain fish such as the Altai osman and Mongolian grayling.