Mauensee is a lake in the canton of Lucerne, Switzerland, near the town Mauensee. Mauensee Castle is built on an islet in the 0.55 km² (136 acre) large lake. It was built in 1605 for the Pfyffer family. ... Found on http://en.wikipedia.org/wiki/Mauensee
1) lake in Switzerland 
Mauensee is a lake in the canton of Lucerne, Switzerland, near the town Mauensee. Mauensee Castle is built on an islet in the 0.55 km² (136 acre) large lake. It was built in 1605 for the Pfyffer family. ...