At the Chalet du Santel, make sure you take a look at the stream. Ÿou will be able to see a vegetated mound, in the shape of a crescent moon, pierced by the stream and colonised by numerous marmots. This mound is an old moraine that the glacier, which once occupied the valley, (about– 15,000 years) left during its retreat. The stream firstly had to create a lake which caused this natural dyke.