Irkutsk, Russia, the administrative center of the Irkutsk Oblast. It is in south-central Siberia on the Angara River west of Lake Baykal. Industries include oil refining, aluminum reduction, and the making of plastics, fertilizer, and chemicals.

Irkutsk was founded as a Cossack fort in 1652. By the early 1700's it had become a center for trade between Russia and China, and a place of exile to which convicts from European Russia were banished. Development was stimulated by the arrival of the Trans-Siberian Railway in the 1890's and the completion of the Irkutsk dam in 1958.

Population: 626,000.