Lake Sempach is a lake in the canton of Lucerne, Switzerland. Its area is about 14.5 km² and its maximum depth is 87 m. A 50 metre-large island named Gamma Insel is located east of Sursee.
Wikipedia https://en.wikipedia.org/wiki/Lake_Sempach
Address 6205, Switzerland
Coordinates 47°8'38.607" N 8°9'19.056" E