Name for the three water bodies located in the northern Alpine foreland: Obersee, Untersee and Seerhein. These are two different but spatially close lakes, which are connected by the section of the Rhine known as the Seerhein. Both lakes have a bank length of 273 km, of which 173 are in Germany, 28 in Austria and 72 in Switzerland. Together they cover 536 km², which stretch between Bregenz (Vorarlberg, Austria) and Stein am Rhein (Schaffhausen, Switzerland). Both lakes are crossed by the Rhine; the main tributary of the Upper Lake is the Alpenrhein, the outlet of the Upper Lake is the Seerhein - which in turn is the main tributary of the Lower Lake - and the outlet of the Lower Lake is the Hochrhein.