Summary Siberia is considered by most to be a remote and frozen wasteland. It covers 13.1 million square kilometers (5.1 million square miles) — almost 10 percent of the Earth's land surface — but with only about three people for every square kilometer, it has one of the world's lowest population densities. It has numerous mountain ranges, such as the Urals and Altai, rivers that flow into the Arctic Ocean when they are not frozen, and a generally cold climate with long winters and short summers. These geographic and climatic features have been significant barriers to the economic development of Siberia, but the region still serves an important strategic function for Russia. First, control of Siberia provides Russia a buffer against the Eurasian steppes, one of two traditional routes of invasion (the other is the North European Plain, the route used by Napoleon's and Hitler's forces).