The Valdai Hills and Smolensk-and-Moscow Heights mark the border of the last pleistocene glaciation. The Central Russian and Volga Region Heights lie more southward; they are characterized by a rather wavy relief and a well developed system of ravines. Wide valleys of the rivers Volga, Don and their confluents are framed by steep right banks, whereas, their left banks are low. In the south the Russian Plain changes into the Pre-Black Sea and Pre-Caspian Sea Lowlands. The Caucasian Mountains are situated between the Black and the Caspian Seas; their peaks reach the height of 5642 m. The Mountains of Caucasus are rather young and dynamic since they occupy the zone where the Euroasian lithospheric plate touches the Arabian one. The Pre-Caspian Sea Lowland's true altitude is below the level of the World Ocean. This Lowland is stretched from the northern Coast of the Caspian Sea right up to Volgograd. The Volga River flows within it over an ancient bottom of the Caspian Sea down to Astrakhan and forms delta with numerous armlets.
In the east the Russian Plain is framed by a system of the Ural Mountains stretched from north to south for more than 2 thousand kilometres. The islands of the Arctic Ocean shelf (the Vaygach and Novaya Zemlya), half-covered with ice, represent their northern extension. The border line between the Europe and Asia goes through the Ural Mountains. They are ancient, strongly destroyed mountains. Average heights the Ural do not exceed 600 m. The highest point - Narodnaya Mountain (in the north) reaches only 1895 m. There are small mountain glaciers in the Polar Ural. In the north the Ural (between Narodnaya Mountain and the latitude of 65 degrees north) is represented only by a single ridge. This ridge is lowering and falling apart into several highlands in the Middle Ural. In the Southern Ural, from the city of Kusa, several sharply defined ridges fork southwest in a fan-shaped manner; their tops rise sometimes up to 1500-1600 m. The western mountainsides of the Ural are, as a rule, flat, wavy, whereas the eastern ones break steeply near the West Siberian Plain. The Ural is rich in minerals.
The West Siberian Plain, one of the greatest flat territories of the globe, is characterized by flat waterlogged surface rising up to 50-100 m above sea level. The plain is drained by the rivers of the Ob River basin, and stretches between the Ural Mountains and the Yenisei River. In its middle part there are strongly waterlogged Middle Ob Lowland and Vasyuganskaya Plain where huge reserves of oil and gas are explored and mined. In the southeast the plain changes into the Altay and Sayan Mountains with the highest point of Belukha Mountain (4506 m). The biggest part of the Eastern Siberia is occupied by the Mid-Siberian Plateau. Its surface is deeply dismembered, and the heights change from 500 to 1700 m above sea level. The highest part of the plateau are the Putoran Mountains (near Norilsk), their height is 1500-1600 m, they are rich in non-ferrous metals deposits. The far north of Eastern Siberia is occupied by the Siberian Lowland and Byrranga Mountains (the Taymyr Peninsula), which are 1100 m high. In the far south the Mid-Siberian Plateau changes into the Eastern Sayan Mountains, up to 3491 m high (Munku-Sardyk Mountain). Beyond Baikal Lake and the Lena River the plateau passes into mountain ridges that reach 4750 m in Kamchatka (the Klyuchevskaya Sopka). Yablonovy Ridge (1680 m above sea level), Stanovoye, Aldanskoye, Koryak Uplands and Kolyma Range, Verkhoyansk and Chersky Ridges (3147 m - Pobeda Mountain) are most prominent here.
The largest rivers of Russia (the Ob, Yenisei, Lena) flow into the Arctic Ocean. The most abounding in water river - the Yenisei (585 cubic km a year), and the most lengthy one - the Ob (from the Irtysh river head) - has the length of 5410 km and annually takes away to the ocean the biggest quantity of solid substances (16 million tons). All Siberian rivers begin in the mountains and flow from south to north. Besides the named rivers, the Northern Dvina, Pechora, Onega and Mezen in the European part of Russia; and Pyasina, Khatanga, Anabar, Yana, Indigirka, Kolyma in the Asian part of the country flow into the Arctic Ocean.
The Volga is the longest (3694 km) European river; it runs into the Caspian Sea. It is connected with the Don (and then with the Azov and Black Seas) by channels, and also with the Baltic and White Seas (through the Neva and Northern Dvina). Despite of abundance of rivers, internal water transport has less than 5 % of all cargo transportations. That may be explained by the fact that the majority of navigable rivers are ice-bound during four, or even nine, months in a year; and also because of the latitudinal direction of freight traffics. Russia possesses the biggest water-power resources which are concentrated mainly in Siberia. Grandiose hydropower projects were carried out on the rivers Angara and Yenisei, but they are rather remote from the western areas that lack energy.
The Caspian Sea in the south of Russia is the biggest lake in the world. Its total area is 376 thousand sq. km, water volume - 78 thousand cubic km, its level is 27 m lower than that of the World Ocean, and the maximum depth - 1025 m. The northern part of the Caspian Sea is very shallow (only 5-8 m). Salinity level of the Caspian Sea (12-13 gr/l) is less that in the oceans; so, both, freshwater and sea fish are found there. During long years this sea has been receding, since water inflow from the rivers running into it, basically from the Volga, Ural, Kura and Terek, is less than evaporation from its surface. Since 1960th this tendency has been even intensified because of creation of water storage ponds and irrigating systems on the Volga River. Consequently, shallowing of spawn areas reduced sturgeon fish catches.
In 1980th years the level of the Caspian Sea began to rise, however, the reasons of these changes are not clear yet. The Baikal in Siberia is the deepest lake in the world; its maximal depth is 1620 m. About 20% of all global fresh-water resources are concentrated here (23 thousand cubic km). The full cycle of natural waters circulation takes 8 or more years. The Baikal length is 636 km, average width - 48 km, the total area - 31,5 thousand sq. km. The lake freezes usually since January till April, and the water temperature does not rise above 13 °C even in summer, except for shallow waters. More than 300 big and small rivers run into this lake, and only one river - the Angara runs out. The greatest number of lakes and natural water reservoirs is concentrated in Northwest Russia and Western Siberia. Many large water reservoirs are created by dams, which blocked wide rivers. Rybinsk, Gorky, Kuybyshev, Saratov and Volgograd storage reservoirs are on the Volga; Nizhnekamsk reservoir - on the Kama; Tsymlyanskoye - on the Don; Novosibirsk - on the Ob; Krasnoyarsk - on the Yenisei; Bratsk and Ust-Ilminsk reservoirs - on the Angara River.