Federsee is a lake located just north of Bad Buchau in the region of Upper Swabia in Southern Germany. It is surrounded by moorland, partially overgrown with reeds. With a size of 33 km2, the area is one of the largest, groundwater fed, connected moorlands in Southern Germany. At its deepest point, Lake Federsee has a depth of 2 metres. Federsee translates to 'feather lake' and its shape resembles that of a feather. However, the origin of its name is locally debated, with one camp defending the shape theory, and another championing the idea that the amount of feathers found on the lake's surface gave rise to its name. The most probable explanation for the origin of the name is, however, the Celtic word "pheder" which means marsh. Therefore, the name refers to the origin of the lake itself and the surrounding landscape. The lake is encircled by the town of Bad Buchau, and the villages of Moosburg, Alleshausen, Seekirch, Tiefenbach, and Oggelshausen.