Sayan is a highland at the southeast of Siberia. Its name originates from the Old Turkic tribe Sayan, who inhabited these mountains. This highland consists of East and West Sayan, which form a great mountain arc, opened to the south. East Sayan is a dividing range between river basins of the Angara and the Yenisei. “Angara” means “jaws of a beast” (i.e. ravine, canyon, fissure) in Buryat, and “Yenisei” is a “great river” in Tungusic. The highest point of Sayan is Mt. Munku-Sardyk (3491m) in its southeast part. Plexus of mountains with the peak “Grandiose”(2922m) was formed in the junction of East and West Sayan.

Sayan mountains began rising with Baikal folding (PR - about 2000 millions years ago) and were completely formed with Caledonian folding (in the beginning of PZ - about 300 millions years ago). They are composed of many different (in mode and formation) rocks, such as granite, syenite, shale, limestone and others. Due to the variety of tectonic processes a number of different mineral resources, including gold, iron ores and marble, were generated there.

West-Sayan upland (West Sayan) stretches for more than 650km from the southeast to the northwest along the south border of Krasnoyarsk Territory. Mt. Karagosh (2930) is the apex of the region. The upland was formed with Caledonian folding. It is composed of different magmatic (granite, syenite, gabbro), sedimentary (sandstone, shale, limestone) and metamorphic (gneiss, crystalline schist, marble) rocks.

Many millions years ago, the climate was much more cold than nowadays. Great Ice Age was in and all mountains were covered with huge glaciers. They were creeping slowly downhill, plowing the earth like giant caterpillar trucks. Behind them were left pointed peaks and ravines with abrupt sides and wide floors (troughs). They are present even where there are no glaciers now.

Later, the climate became warmer and some glaciers had thawed. They filled with meltwater a number of topographic depressions, left by ancient glaciers. That’s the origin of numerous glacier lakes in the mountains.