{{infobox body of water , name = Rheinsee , image = Ermatingen.jpg , caption = View of the Rheinsee near

Ermatingen Ermatingen is a municipality in the district of Kreuzlingen in the canton of Thurgau in Switzerland. History The Stone Age Westerfeld and Büge shoreline settlements were discovered in 1861 and studied extensively 1981-83, with finds from the P ...

, location =

Baden-Württemberg Baden-Württemberg (; ), commonly shortened to BW or BaWü, is a German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants across a ...

, coordinates = {{coord, 47, 39, 45, N, 08, 57, 37, E, type:landmark_region:DE-BW, format=dms, display=inline,title , pushpin_map = Germany , inflow =

Seerhein The Seerhein ("Lake Rhine") is a river about four kilometres long, in the basin of Lake Constance. It is the outflow of the Upper Lake Constance and the main tributary of the Lower Lake Constance. The water level of the lower lake is about 30& ...

, outflow =

High Rhine The High Rhine (german: Hochrhein) is the name used for the part of the Rhine that flows westbound from Lake Constance to Basel. The High Rhine begins at the outflow of the Rhine from the Untersee in Stein am Rhein and turns into the Upper Rhine ...

(''Hochrhein'') , islands = , cities = , elevation = {{convert, 395, m , area = , length = {{convert, 20, km , width = , depth = , max-depth = {{convert, 45, m , volume = , shore = The

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , source ...

leaves that part of

Lake Constance Lake Constance (german: Bodensee, ) refers to three bodies of water on the Rhine at the northern foot of the Alps: Upper Lake Constance (''Obersee''), Lower Lake Constance (''Untersee''), and a connecting stretch of the Rhine, called the Lak ...

known as the Upper Lake or Obersee as the

near

Konstanz Konstanz (, , locally: ; also written as Constance in English) is a university city with approximately 83,000 inhabitants located at the western end of Lake Constance in the south of Germany. The city houses the University of Konstanz and was t ...

. After six kilometres it forms the Rheinsee, through which the river current flows. At its outflow is the island of Werd with its Franciscan monastery. The Rheinsee, together with the Zeller See and the

Gnadensee The Gnadensee is part of Lower Lake Constance (german: Untersee), the western part of the lake. Description The Gnadensee lies between Allensbach in the north and the island of Reichenau in the south. In the west it extends to the Mettnau peni ...

, which surround the

island of Reichenau Reichenau Island () is an island in Lake Constance in Southern Germany. It lies almost due west of the city of Konstanz, between the Gnadensee and the Untersee, two parts of Lake Constance. With a total land surface of and a circumference o ...

, form the Untersee. The latter, together with the Seerhein, are considered part of Lake Constance. In the specialist literature, however, it is also stated that the Rhine leaves Lake Constance at Konstanz. According to this proposition, the Untersee would be a separate lake. The Rheinsee forms the international border between

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

and

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

. The eastern part of the Rheinsee is the Bay of Ermatigen (''Ermatinger Bucht''). The greatest depth of the Rheinsee, 45 metres, is simultaneously the deepest point of the entire Untersee.ikgb Internationale Gewässerschutzkommission für den Bodensee: Limnologischer Zustand des Bodensees, Bericht No. 40
p. 43 At the outflow of the Rheinsee lies

Stein am Rhein Stein am Rhein (abbreviated as Stein a. R.) is a historic town and a municipality in the canton of Schaffhausen in Switzerland. The town's medieval centre retains the ancient street plan. The site of the city wall, and the city gates are preserve ...

, a little town situated on either side of the river.

References

Geography of Lake Constance