The Pragel Pass links the Muota Valley in the canton of Schwyz with the Klön Valley in the Glarus region. The tour begins at the top of the pass. The ascent via Alp Butzen with its herds of cattle leads continuously away from the meadows as you enter the bleak and weird karst region. The name "Silberen" (or silver) refers to the bright colour of the rock. What is so special about this rocky area: it has everything from bare cliffs to subalpine forest, and it also contains Switzerland's largest karrenfield (eroded limestone terrain).

As you walk across this protected landscape, you can hear marmots whistling. Chamois also understand the signal and flee for cover. It’s hard to imagine, but evidence shows that red deer and ibex were the prey of primeval hunters here 10'000 years ago. Look for traces of an ancient settlement near the cross on the summit. The breathtaking panoramic view and tranquillity are ideal for lingering. From here the visibly marked trail traverses the alpine plateau eastwards, finding its way through a karstic landscape formed by water and shrouded in legend. With a little luck, ptarmigan can be seen here.

Another unusual feature: one of the world's longest cave systems – the Hölloch – stretches below hikers' feet. The caves extend for about 200 kilometers beneath the Silberen karst zone. Suddenly, we find ourselves in the expansive sheepwalks on Silberenalp, where countless small ponds glisten in the sunlight. The way back to Pragel features panoramic views of the Klön Valley with the deep-blue mountain lake.