Irkutsk Oblast in the context of "Sayan Mountains"

Lake Baikal is a rift lake and the deepest lake in the world. It is situated in southern Siberia, Russia between the federal subjects of Irkutsk Oblast to the northwest and the Republic of Buryatia to the southeast.

At 31,722 km (12,248 sq mi)—slightly larger than Belgium—Lake Baikal is the world's seventh-largest lake by surface area, as well as the second largest lake in Eurasia after the Caspian Sea. However, because it is also the deepest lake, with a maximum depth of 1,642 metres (5,387 feet), Lake Baikal is the world's largest freshwater lake by volume, containing 23,615.39 km (5,670 cu mi) of water or 22–23% of the world's fresh surface water, more than all of the North American Great Lakes combined. It is also the world's oldest lake at 25–30 million years, and among the clearest. It is estimated that the lake contains around 19% of the unfrozen fresh water on the planet.

The Buryats are a Mongolic ethnic group native to southeastern Siberia who speak the Buryat language. They are one of the two largest indigenous groups in Siberia, the other being the Yakuts. The majority of the Buryats today live in their titular homeland, the Republic of Buryatia, a federal subject of Russia which sprawls along the southern border and partially straddles Lake Baikal. Smaller groups of Buryats also inhabit Ust-Orda Buryat Okrug (Irkutsk Oblast) and the Agin-Buryat Okrug (Zabaykalsky Krai) which are to the west and east of Buryatia respectively as well as northeastern Mongolia and Inner Mongolia, China. Traditionally, they formed the major northern subgroup of the Mongols.

Buryats share many customs with other Mongolic peoples, including nomadic herding, and erecting gers for shelter. Today the majority of Buryats live in and around Ulan-Ude, the capital of the Buryat Republic, although many still follow a more traditional lifestyle in the countryside. They speak a central Mongolic language called Buryat. UNESCO's 2010 edition of the Atlas of the World's Languages in Danger classifies the Buryat language as "severely endangered".

Buryatia, officially the Republic of Buryatia, is a republic of Russia located in the Russian Far East. Formerly part of the Siberian Federal District, it has been administered as part of the Far Eastern Federal District since 2018. To its north lie Irkutsk Oblast and Lake Baikal, the deepest lake in the world; Zabaykalsky Krai to the east; Tuva to the west and Mongolia to the south. Its capital is the city of Ulan-Ude. It has an area of 351,300 square kilometers (135,600 sq mi) with a population of 978,588 (2021 Census). It is home to the indigenous Buryats.

Tuva (/ˈtuːvə/; Russian: Тува [tʊˈva]), or Tyva (/ˈtɪvə/; Tuvan: Тыва [tʰɤ̀ʋɐ]), officially the Republic of Tyva, is a republic of Russia. Tuva lies at the geographical center of Asia, in southern Siberia. The republic borders the federal subjects of the Altai Republic, Buryatia, Irkutsk Oblast, Khakassia, and Krasnoyarsk Krai, and shares an international border with Mongolia to the south. Tuva has a population of 336,651 (2021 census). Its capital city is Kyzyl, in which more than a third of the population reside.

Historically part of Outer Mongolia as Tannu Uriankhai during the Qing dynasty, the last imperial dynasty of China, Tuva broke away in 1911 as the Uryankhay Republic following the Xinhai Revolution, which created the Republic of China. It became a Russian protectorate in 1914 and was replaced by the nominally independent Tuvan People's Republic in 1921 (known officially as Tannu Tuva until 1926), recognized only by its neighbors the Soviet Union and Mongolia, before being annexed into the former in 1944. A majority of the population are ethnic Tuvans who speak Tuvan as their native tongue, while Russian is spoken natively by the Russian minority; both are official and widely understood in the republic. The Great Khural is the regional parliament of Tuva.

The Mongolian Plateau or Altai Plateau is an inland plateau in East Asia covering approximately 3,200,000 square kilometers (1,200,000 sq mi). It is bounded by the Greater Hinggan Mountains in the east, the Yin Mountains to the south, the Altai Mountains to the west, and the Sayan and Khentii mountains to the north. The plateau includes the Gobi Desert as well as dry steppe regions. It has an elevation of roughly 1,000 to 1,500 meters (3,300 to 4,900 ft), with the lowest point in Hulunbuir and the highest point in the Altai.

Politically, the plateau spans all of Mongolia, along with parts of China and Russia. Inner Mongolia and parts of the Dzungarian Basin in Xinjiang encompass the Chinese portion of the plateau. In Russia, the plateau forms Transbaikal, part of Buryatia, and the southern Irkutsk Oblast. The Mongolian Plateau comprises the majority of the area known as the Mongol heartland.

Irkutsk Time (IRKT) is the time zone eight hours ahead of UTC (UTC+08:00) and 5 hours ahead of Moscow Time (MSK+5).

The time zone covers Buryatia and Irkutsk Oblast.

The Extreme North or the Far North is a large part of Russia located mainly north of the Arctic Circle and boasting enormous mineral and natural resources. Its total area is about 5,500,000 square kilometres (2,100,000 sq mi), comprising about one-third of Russia's total area. Formally, the regions of the Extreme North comprise the whole of Chukotka Autonomous Okrug, Kamchatka Krai, Magadan Oblast, Murmansk Oblast and Sakha, as well as certain parts and cities of Arkhangelsk Oblast, Irkutsk Oblast, Khabarovsk Krai, Komi Republic, Krasnoyarsk Krai, Republic of Karelia, Sakhalin Oblast, Tuva, Tyumen Oblast, as well as all islands of the Arctic Ocean, its seas, the Bering Sea, and the Sea of Okhotsk.

Due to the remoteness and the harsh conditions of the area, since the Soviet times people who work there have traditionally been entitled by the Russian government to higher wages and many other benefits, including earlier retirement age, than workers of other regions. As a result of the climate and environment, the indigenous peoples of the area have developed certain genetic differences that allow them to better cope with the region's environment, as do their cultures.