Derborence Lake was created as a result of a massive landslide near Sion in the 18th century. The eponymous valley is a nature reserve with a pristine beauty that fascinates geologists, botanists and nature lovers alike.
The vacation region around the Black Lake and in the Eastern Freiburg Pre-Alps (Voralpen) is well-known for its authenticity and its wild, romantic natural landscape, which includes the dark appearance of the Black Lake and the Brecca Abyss, an Alpine valley formed by glaciers.
A calm lake lies near the Oberalp Pass. This lake's water flows clear and fresh into the valley. The Tomasee (Lake Toma) is considered to be the source of the Rhine. And it is only here that the river that flows through four countries can still be crossed with a single step.