Located 45 kilometers south of Ulgii, it stretches from southeast to northwest, the lake depression is of tectonic origin, the source of the reservoir is glacial, and it is one of the largest lakes in Mongolia. Tolbo soum is located at the southern end of the lake. It covers an area of 185 square kilometers, the longest is 21.5 kilometers, the widest is 6 kilometers, and is 2,080 meters above sea level.

There are several small islands. The largest is Gichgenii Tolgoi, which is only 4 meters above sea level.

It is irrigated by about 10 rivers flowing from the surrounding mountains, and the excess water is discharged through the Turgen River into the Umnu River, a western tributary of the Khovd River.

The story near the lake:

There is a story known as the Battle of Tolbo Lake, which is related to the events of the 1921 People's Revolution.

 It is a historic event that 160 Mongol-Soviet troops led by Khasbaatar and Baikalov fought on the shores of Lake Tolbo against about 2,400 White Russian troops led by Baron Ungern's Kaigaradov and Bakich. In this unbalanced battle, the Mongol-Soviet soldiers were seized and swore an oath of allegiance and stayed together for 42 days, and finally decided to break the siege and succeeded.

Thus a plaque has been erected in their memory and is on top of a hill along the main road.

There is also a monument to Khasbaatar and Baikalov 1 km behind the Tolbo soum center.