郭守敬
Kunming Lake is a manmade lake whose predecessors were called "Wengshan (Jar Hill) Pond" and "Xihu Lake". They were reservoirs which had been used as sources of water both for the city and irrigation of fields over a period of 3,500 years. Guo Shoujing, a famous astronomer and engineer in his time, developed it into a reservoir for the capital of the Yuan Dynasty in 1291. The conversion of the area into an imperial garden was commissioned by the Qianlong Emperor with the work being carried out between 1750 and 1764. In the course of creating the gardens, the lake area was extended by a workforce of almost 10,000 laborers.