Hintersee south shore

Due to its mostly flat and gravelly shores, the Hintersee is ideal for swimming, boating or paddling.

The Hintersee at the foot of the Reiteralpe and the Hochkalter was formed around 3,500 to 4,000 years ago when a rock slide from the Blaueistal from the Hochkalter massif, which covers an area of 75 hectares, dammed the Klausbach, which rises at Hirschbichl, and at the same time created the magic forest. In order to prevent further siltation caused by the debris carried along, the Klausbach was led around the Hintersee around 1900 to its overflow, the Sillersbach, and finally flowed into the Ramsauer Ache. Nevertheless, the lake today only has a third of its original area.
Source: Wikipedia

The lake, which has been proven to have been created in the Bronze Age by a massive rock fall, can be walked around in around 45 minutes. The water is ice cold and the lake is up to 18 m deep.