Irkutsk OblastIrkutsk Oblast (Irkutskaya oblast; Erkhüü mojo) is a federal subject of Russia (an oblast), located in southeastern Siberia in the basins of the Angara, Lena, and Nizhnyaya Tunguska Rivers. The administrative center is the city of Irkutsk. It borders the Republic of Buryatia and the Tuva Republic in the south and southwest, which separate it from Khövsgöl Province in Mongolia; Krasnoyarsk Krai in the west; the Sakha Republic in the northeast; and Zabaykalsky Krai in the east. It had a population of 2,370,102 at the 2021 Census.
PermafrostPermafrost () is soil or underwater sediment which continuously remains below for two or more years. Land-based permafrost can include the surface layer of the soil, but if the surface is too warm, it may still occur within a few centimeters of the surface down to hundreds of meters. It usually consists of ice holding in place a combination of various types of soil, sand, and rock, though in ice-free ground, perennially frozen non-porous bedrock can serve the same role.
SiberiaSiberia (saɪˈbɪəriə ; Sibir', sjɪˈbjirj) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed part of the sovereign territory of Russia and its various predecessor states since the centuries-long conquest of Siberia, which began with the fall of the Khanate of Sibir in the late 16th century and concluded with the annexation of Chukotka in 1778. Siberia is vast and sparsely populated, covering an area of over , but home to only one-fifth of Russia's population.
Siberian River RoutesSiberian River Routes were the main ways of communication in Russian Siberia before the 1730s, when roads began to be built. The rivers were also of primary importance in the process of Russian conquest and exploration of vast Siberian territories eastwards. Since the three great Siberian rivers, the Ob, the Yenisey, and the Lena all flow into the Arctic Ocean, the aim was to find parts or branches of these rivers that flow approximately east-west and find short portages between them.
SakhaSakha, officially the Republic of Sakha (Yakutia), is the largest republic of Russia, located in the Russian Far East, along the Arctic Ocean, with a population of one million. Sakha comprises half of the area of its governing Far Eastern Federal District, and is the world's largest country subdivision, covering over 3,083,523 square kilometers (1,190,555 sq mi). Yakutsk, which is the world's coldest major city, is its capital and largest city.
Trans-Siberian RailwayThe Trans-Siberian Railway, historically known as the Great Siberian Route and often shortened to Transsib, is a large railway system that connects European Russia to the Russian Far East. Spanning a length of over , it is the longest railway line in the world. It runs from the city of Moscow in the west to the city of Vladivostok in the east. During the period of the Russian Empire, government ministers—personally appointed by Alexander III and his son Nicholas II—supervised the building of the railway network between 1891 and 1916.