Fed by the Rosenlaui glacier, the River Weissenbach has carved an impressive glacial gorge some 70m deep. The erosion has created some surprising features: note the formations resembling an elephant's head, a cathedral dome, even General de Gaulle's profile. The vertiginous path follows the edge, from where the water below can be seen rushing fiercely through the gorge. The route ends at Schwarzwaldalp, where an entire slope is planted with maple trees.