Once called Bavarian Sea, the Chiemsee is a freshwater lake in Bavaria, Germany, surrounded by Rosenheim, Germany, Salzburg, as well as Austria.
With an elevation of 518 meters and 1699 feet, the lake is the largest lake in Bavaria. Also it is with a length of 15 km, and a width of 8 km, covering an area of 82 square kilometers. There are 3 islands in the lake, with limpid water, a large number of trouts, carps, as well as other kinds of fish. However, it is forbidden fishing in the lake.

It is said that numerous lakes in the Alps are like fragments of a broken mirror. All debris scattered in the mountains, of which the greatest one is the Chiemsee.
The Chiemsee was formed like many other pre-alpine lakes in about 10,000 years ago at the end of the last Ice Age by a glacier. Originally, the lake covered an area of 240 km, about three times as its present area. Then the area shrank to about 200 hectares within 100 years. The water level was lowered by about one meter and some large areas of dry land were reclaimed in 1904 .
The Chiemsee possesses three islands, of which are men islands, women islands as well as vanilla island which are still uninhabited. The largest one is the men island, which is famous for the monastery. There also stands a palace built by Ludwig II, with a style imitating the famous Palace of Versailles in France.

Germany made some strict rules to prohibit to the discharge of all kinds of eutrophic water into the lake. At the same time, the Chiemsee District is in collaboration with the International Water Conservation Committee, jointly developing the project of water purification, reducing the content of phosphorus in the lake. They took measures to protect the lakeshore environment, such as reasonable development, strict emission standards, limit of wastewater emissions by enterprises and individuals.