Tannu-Ola is a mountain system (ridge) in Southern Siberia, in the south of Tuva. It consists of the eastern and western parts. The range stretches from east to west along the border with Mongolia. The average height is 2500-2700 m. The peaks with eternal snows are absent. The northern slopes, which are a watershed for Yenisei And covered with cedar-larch taiga, facing East Sayans. On the southern slopes, the steppe prevails. The western end of Tannu-Ola is adjacent to Altai Mountains. The rivers flowing from the ridge are insignificant. Geological rocks are represented by sandstones, schists, conglomerates (Western Tannu-Ola), effusive sedimentary rocks and granites (Eastern Tannu-Ola). Earlier in the mountains there was mining of cobalt. The total length of Tannu-Ola from the West to the East is about 300 km, the height is up to 3061 m. The southern slope facing the hollow of the inundated Lake Ubsu-Nur is short and steep; Sowing. (To the Tuva basin) stretched, dismembered by the valleys of the tributaries of the Yenisei. The tops are often wide dome-shaped. In the north. Slopes up to heights 2000-2200 m cedar-larch taiga, to the south. Slopes of the steppe; In the terminal and vertex belts mountain tundra, stone collapse. The mountainous system is dominated by an average relief with a height of up to 2500-2700 m (the largest is 3061 m). It is composed of sandstones, shales, conglomerates (Western Tannu-Ola), effusive-sedimentary rocks and granites (Eastern Tannu-Ola). On the northern slopes (up to a height of 2000-2200 m.) - cedar-larch taiga, on the southern slopes - steppe vegetation; On pologovolnistoy top surface - stone placers and high tundra.