The Republic of Buryatiya is situated in the Eastern Sayan Mountains. It lies mainly to the east of Lake Baikal, although it also extends westwards along the international boundary with Mongolia in the south, to create a short border with the Republic of Tyva in the extreme west. Irkutsk Oblast lies to the north and west, Transbaikal Krai to the east. Buryatiya’s rivers mainly drain into Lake Baikal, the largest being the Selenga, the Barguzin and the Upper Angara, but some, such as the Vitim, flow northwards into the Siberian plains. The territory declared its sovereignty in 1990 and was renamed the Republic of Buryatiya in 1992. In 2019 Buryatiya’s gross regional product amounted to 285,832m. The Republic of Sakha is situated in eastern Siberia on the Laptev and Eastern Siberian Seas. The Yakuts, also known as the Sakha, traditionally a semi-nomadic people, were historically known as the Tungus, Jekos and the Urangkhai Sakha.