Beautiful lake in the world one of them is Lake Constance

Lake Constance (German: Bodensee) is a combination of three lakes that restrict Switzerland (Canton St. Gallen and Thurgau), Germany (Baden-Württemberg and Bayern) and Austria (the state of Vorarlberg). Largest lake is Obersee ("Upper Lake") by extending to the northwest corner called Überlinger See, then Untersee ("Lake Bottom"), and an elongated section that separates the two is Rheinsee. Total overall has an area of 571 km ² (about one-fifth of Lake Toba) and the depth of 253m at its deepest point. This lake is the third largest lake in the surrounding countries.

This lake had frozen in 1795, 1830, 1880, and 1963. The main island in the lake is the island of Mainau, the island of Reichenau, and the island of Lindau. Its name comes from one of the city on its western edge, Konstanz am Bodensee.
Water was added to the lake from the River Rhine in the south side (from Switzerland) and releases water to the river was also on the west side, limiting wilayah Switzerland and Germany.