The Circum–Baikal railway is a historical railway in the Irkutsk region of Russia. It runs along the Northern shore of the Southern extremity of Lake Baikal from the town of Slyudyanka to the Baikal settlement. Until the middle of the 20th century the Circum–Baikal railway was part of the main line of Trans–Siberian Railway; later on, however, a duplicate section of the railway was built. Sometimes called a unique achievement in engineering, the Circum–Baikal is one of the picturesque sights of the area around Lake Baikal.

Irkutsk Oblast is a federal subject of Russia, 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.