Irkutsk (421), a central Siberian province, separated from China by the Sayan Mountains; it has Lake Baikal on the E., Yenisei and Yakutsk on the W. and N.; a rich pastoral country, watered by the navigable rivers Angara and the Lena, agriculture, cattle rearing are prosperous industries; there are gold, iron, and salt mines; one-third of the population are forced colonists; the capital, Irkutsk (45), is the seat of government for Eastern Siberia, an ecclesiastical centre, and the chief emporium of commerce; it is the finest city in Siberia.