What to do in summer > Sports and leisure > Natural world > Illgraben


Chandolin - Illgraben is Switzerland’s most significant active debris flow site. It is accessed on foot; once you have reached the ridge, all you have to do is admire the view and get carried away by the feelings it evokes…

Illgraben is a huge cirque or rocky bowl set high above the Rhone valley. It is the result of a landslide in the 14th century from the effects of erosion. It is also one of the most active debris flow channels in the Swiss Alps - the flows can be observed several times a year.

The Illgraben basin has a surface area of 10 km2. This hollow formed by erosion is made up of :

  • Quartzite
  • Calcareous deposits
  • Dolomite

The rocky basin of Illgraben is almost completely lacking in vegetation and represents an amazing alluvial landscape. It has a precipice more than 1500 m deep. The enormous pale yellow and reddish gash further increases the sensation of emptiness. Always moving, this breach is growing a little more each year.


From Chandolin :

1 hour’s walk Access gained from the Illsee lake

View from the ridge :

1500 m void, looking straight out towards the Rhone valley

Caution should be exercised with children and in case of bad weather

Anniviers Tourisme - Chandolin Office
+41(0)27 476 17 15