屈韦西湖是芬兰的湖泊，位于该国南部，由南萨沃尼亚区负责管辖，海拔高度100.65米，面积129.95平方公里，蓄水量5.7亿立方米，平均水深4.39米，最大水深35.25米。

• Finnish Environment Institute: Lakes in Finland
• Etelä-Savon ympäristökeskus: Saimaa, nimet ja rajaukset （芬兰文）

Kyyvesi (transl.Viper Water) is a rather large lake in the Southern Savonia region of Finland. Spite its size (129,95 km²) it's very shallow and extremely rocky. Motorboating is recommended only for very experienced boaters as many of the rocks have not been mapped. Also, the limited amount of landing sites is a hindrance in moving swiftly through the lake. A general bathymetric chart was completed in 2006. Canoes, kayaks and rowing boats are recommended for visitors. There is a two-lake canoein route Kyyvesi–Puula with nice little harbours. The water is dark for the catchment area is mostly swampy terrain. Locals claim that two sorts of zander fishes are living in the lake.