A lucid, razor-sharp line carving across the mountain faces catches the thoughtful observer's eye where the three Swiss provinces St. Gallen, Glarus and the Grisons meet. This natural viaduct belongs to the most fantastic geological protrusions of the thrust. The prominent three-dimensional disclosure of the structures and divergent indication of a typical tectonic mechanisms have to a colossal extent manipulated scientific research and understanding of mountain development. The Niderenbach stream, on its way to the Legler hut, grooved its subversive path in the younger, lower-lying, schistose, soft flysch rock. The much older Verrucano has now been much battered and only vestiges visible to the left and right of the "Chärpfbrücke". At low water, you can hike along the 50m-long, 3m-high subversive watercourse at your own risk!