Erosion caused the mountain to collapse and the vast, pale yellow and reddish rock basin to form, which becomes bigger every year. From the Grabenrad or the Illhorn (2,716 m) there are "fear inspiring" yet stunning views down into the Rhone valley.
Here is a chance for unique mountain adventures and mountain railway experiences - the Walen Trail is a sophisticated pleasure tour with panoramic views.
Vast moorlands and pine forests characterise the landscape on the Alp Flix. Hikers appreciate the charm of this high plateau with its gurgling brooks and flower-covered meadows. The circular walk from Sur to the idyllic moorland lakes, Lake Neir and Lake Blos, reveals the extraordinary beauty of this "treasure chest of nature".