Lake Dian, lake lying to the south of Kunming in Yunnan province, southern China. Lake Dian is located in Yunnan’s largest grouping of lake basins, in the eastern part of the province and south of the Liangwang Mountains, which reach an elevation of some 8,740 feet (2,664 metres). The lake is about 25 miles (40 km) from north to south, 8 miles (13 km) wide, and 25 feet (8 metres) deep. The mountains rise steeply from the eastern and western shores, but to the north is an extensive alluvial plain, which has been intensively irrigated since the Yuan (Mongol) dynasty (1279–1368) and the early part of the Ming dynasty (1368–1644). Before that time the region was under Chinese influence only for limited periods of time. The area was settled by sedentary agricultural peoples as early as the 2nd century bc. It was successively the centre of the independent state of Dian, which became tributary to the Han dynasty (206 bc–ad 220) after 109 bc, and of the states of Nanchao (8th–10th century), Dali (10th–13th century), and Houli (11th–13th century).