The river has its source in the western hills of Baikal mountain ridge and flows into the Arctic Ocean. The Lena reaches 9,3 miles width in its middle stream, and about 15,6 miles in its lower stream. The Lena delta is so vast that it is included in the Guinness book of records. The Lena’s tributaries – rivers Vitim, Olyokma, Aldan and Viluy are bigger than some of the European rivers.

     Lena – is the only big river n the world flowing on the permafrost area. The river nourishes vast areas with different natural habitats having mostly strict continental climate. The hydrology of the river is unique and is characterized by immense spring floods..

    The valleys along the river have long been populated. All the three great valleys in its middle stream are a cradle for productive livelihood, the sources for ethnic cultures and traditional economies. Centuries ago the lands along the river were first inhabited by ancient paleo-asiatic tribes and then later became a home for the Sakha (Yakut) people.

    The biodiversity provided by the Lena’s basin is acknowledged in Russia. There are three federal nature reserves – one protecting its source, “Baikalo-Lensky Nature Reserve”, one for its middle stream area, “Olyokminsky Nature Reserve”, and one for its delta, “Ust-Lensky Nature Reserve”. All of the three protected areas are habitats for numerous species of birds, plants and animals included in the Red Book of Rare Species of Russian and the world. According to the scientists, the Lena’s banks are a habitat for the grater part of all rare species of medical herbs of Yakutia. There are many endemic species of herbs - such plants, as Redowskia sophiifolia, Ceratoides lenensis (Eurotia lenensis Kumin.), Taraxacum lenense Tzvel. (dandelion), Oxytropis karavaevii Jurtz, and others grow only in the valleys along the river. The river is also a home for about 70 % of rare birds species of Yakutia. Te black crane is one of the species close to extinction. The endangered species include birds as black brant and pilgrim-falcon.

    Lena– is one of the cleanest rivers in the world. It still flows in its original bed as it was much time ago. At present, there are no hydro-power station, dams, or other types of industrial constructions affecting the river’s environment. At places with no settlements one can scoop a palm of its water and drink it right away..

     The Lena river – is a natural source of fresh water, which every year becomes less and less available all over the planet.