The Lena is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean. Permafrost underlies most of the catchment, 77% of which is continuous. It is 4,294 kilometres (2,668 mi) long, and has a drainage basin of 2,490,000 square kilometres (960,000 sq mi). The Lena is the eleventh-longest river in the world, and the longest river in Russia.
Read article on Wikipedia