Europe's largest subterranean lake that can be sailed upon lies between Sion and Sierre. The water grotto is easily accessible and there is a boat tour for viewing it. The guides on the boat tell visitors about the history of the cave and its geology.
If brooks and rivers run only sluggishly above ground, hydropower is nearly impossible to harness. That is why the inhabitants of the valley of Le Locle began to use subterranean streams. This is how the cave mills of "Col-des-Roches" arose.
In three day-tours from Eastern Switzerland to Geneva. The tour begins in St. Margrethen and travels via Heiden and Trogen to Appenzell. Nowhere else in Switzerland does the landscape change from a hilly region, such as the one in the Mittelland, to the Alpine mountain world as abruptly as in the Alpstein region. The tour continues via Urnäsch to Neu St. Johann in Toggenburg, the valley of the Churfirsten.