Mongolia is a mountainous country. Erosive mountain relief and depressions of tectonic origin formed during the late Cretaceous and Early Quaternary periods are numerous in the northern regions of the country. Eighty per cent of all Mongolian territory is situated about 1,000 meters above sea-level. The surface of Mongolia comprises the biggest parts of the Mongol Altai Mountains, Great Lakes Depression, mountains surrounding Lake Khuvsgul, the Khangai mountain range, Orkhon-Selenge river basin, Khentii Mountain, Dornod Steppe and Great Khyangan mountain.

The Mongol Altai Mountains are situated in the western part of Mongolia stretching for 600-650 kilometres and are characterised by thin hills, hollows and straight precipitous crags, which have a height of more than 4,000 meters. The Khuiten peak of the Altai Tavan Bogd Mountain is the highest point of Mongolia. The peak is 4,374 meters above sea-level. There are glaciers in the highest parts of the Mongol Altai. The Great Lakes Depression is situated in the eastern part of the Mongol Altai and consists of a few hollows with bigger lakes.

Khuvsgul Lake was formed in the Khuvsgul Depression. The Khuvsgul Mountains are situated on the northern side of the Khangai Mountain range and were formed by Lakes Ulaan Taiga and Khoridol Saridag, 3491 meters above sea level. A zone in the south, through which the rivers of the Tes and Selenge basins flow, separates the Khuvsgul Mountains. This zone was named the "1905 splitting zone" after a strong earthquake there in 1905. The Khangai Mountains are situated in the centre of Mongolia. 

The highest peak of the Khangai Mountain range is the Otgontenger Mountain, which is situated in the western part of the mountain range and is 4021 meters above sea level. There is a little glacier on the top of the Otgontenger. There are waterfalls in the rivers with their source in the Khangai Mountain range, and the valley of the rivers is rich in rapids and waterfalls, which occur frequently. The Ulaan Tsutgalan Waterfall on the River Orkhon is one of the biggest waterfalls in Mongolia. The Lakes Valley is situated in the thin depression between the mountains at the southern point of the head of the Khangai mountain range. The mountains of the Gobi-Altai continue 600 kilometres at the southward end of the Lakes Valley. The highest point of the Gobi-Altai Mountains is the Great Bogd Mountain, the height of which is 3957 meters.