Qiandao Lake, a human-made lake located in Chun'an County, Zhejiang Province, China, was formed after the completion of the Xin'an River hydroelectric station in 1959. 1,078 large islands dot the lake and a few thousand smaller ones are scattered across it. The lake covers an area of 573 km2 (221 sq mi) and has a storage capacity of 17.8 km3 (4.3 cu mi). The islands in the lake cover about 86 km2 (33 sq mi).
Qiandao Lake is used to produce the Nongfu Spring brand of mineral water. Over 90% of the area is forested. The islands in the lake include Bird Island, Snake Island, Monkey Island, Lock Island (featuring supposedly the world's biggest lock), and the Island to Remind You of Your Childhood.
The lake has made Zhejiang a popular area for tourists. As a result, housing development has increased in the area since the late 1990s.
The dam creating the lake is located at 29°29′01″N 119°12′48″E / 29.48361°N 119.21333°E and is 105 m (344 ft) tall with a crest length of 466.5 m (1,531 ft). Xin'an Dam was the first dam constructed in China with a height greater than 100 m (328 ft) and its power plant has an installed capacity of 845 MW.