The Lena River is one of the longest rivers in Russia, stretching for over 4,400 kilometers. It is also known by other names such as Lena-Angara, Lena-Kirenga, and Vilyuy River. The indigenous Yakut people call it "Usun-Kyuyol" which means "Big River". The river is named after the Russian explorer and geographer Dmitry Yuryevich Lachinov, who was the first to map its course in detail. In Russian, the river is called "Река Лена" or simply "Лена". The river is also referred to as the "Siberian Amazon" because of its huge waterway and the diverse flora and fauna that inhabit its banks.