German Bodensee ancient Lacus Brigantinus Lake, bordering Switzerland, Germany, and Austria. Occupying an old glacier basin at an elevation of 1,299 ft (396 m), it has an area of 209 sq mi (541 sq km) and an average depth of 295 ft (90 m). It forms part of the course of the Rhine River, and by the Middle Ages it was a major traffic hub. Spectacular Alpine scenery makes the lakeshore a popular resort area. The remains of Neolithic lake dwellings are found in the area