Located in the Erdenehairkhan sum area of Zavkhan province, "Ulaagchni Khar" lake is a unique beautiful place surrounded by sand dunes in the north and reeds in the south. It is 110 km from the center of the province and 80 km north of Erdenehairkhan Sum. It is surrounded by the majestic mountains of Tovhosh.

The depth of the lake "Ulaagchni Khar" is 48m, the length is 30km, and the width is 5-10km. There are three Avgash islands in the middle of the lake, which are more than 2500 meters high, which are nests of migratory birds. About 13 types of migratory birds visit the lake every year.

"Khar Nuur" is a smaller but deeper lake than "Khar-Us" lake. "Khar-Us" lake gives its excess water to "Khar" lake through Chono Kharaykh river. But "Khar" lake gives its excess water to Durgan lake through Khom strait, and to Zavkhan river through Tathan-Teel river. The 12km-long Tathan-Teel River not only carries excess water from "Khar" Lake, but also serves as the single channel for conveying water from all the rivers and lakes of Mongolian Altai belonging to "Khar-Us" Lake and Hovd River system to Khyargas Lake. At the end of October, it freezes and the thickness of the ice reaches 110 cm, and the smooth ice always shines. Black algae grows evenly along the bottom of the lake, and light-colored silt covers most of the bottom. Locals honor the beauty of the surrounding lake and call it the "Pearl of the Lake". A flower called "shunh" grows above the lake bed, making the fair look perfect.