Physical Features: surround by mountains, Yu River running across from south to north, and its central and south part are occupied by plains, topography slopes down from northwest to southeast.
Population: 926,000
Area: 2,071 sq km
People: Han
History: once served as capital during the North Wei dynasty, named Heng'an county in North Qin dynasty, renamed Yunzhong in Sui dynasty, became Datong government office in Ming and Qing dynasties. After the founding of P.R.C., belongs to Shanxi province.
Climatic Features: dry and windy, big temperature difference between day and night, annual rainfall 400-500mm, and frost-free 125 day
Average Temperature: 6.4 degree C
Rainfall: an annual precipitation of 400-500mm