ZAISAN, or ZAISANSK  , a town of Russian Central Asia, in the province of Semipalatinsk, near the Chinese frontier, at an altitude of 2200 ft. and near the S.E. corner of Lake Zaisan . Pop . (1897) 4471• Lake Zaisan, situated in an open valley between the Altai range on the north-east and the Tarbagatai on the south, lies at an altitude of 1355 ft . It has a length of 65 m., a width of 14 to 30 m., an area of 707 sq. m., and a maximum depth of 50 ft . Its water is fresh, as it receives the Black Irtysh and the Kendyrlyk from the east, and several small streams from the west, all of which leave the lake at its north-west extremity by the White Irtysh . The fisheries, which yield abundantly, are in the hands of the Siberian Cossacks . The lake is generally frozen from the beginning of November to the end of April .