Discover the undergroud lake
of St-Leonard

Discovered in 1943 and in operation since 1949, this is one of the most fascinating places underground, just 10 minutes from Sion.

The “Lac Souterrain de St-Léonard” is located in Switzerland, between Sion and Sierre, in the heart of the Valais Alps. A privileged witness to the formation of the Alps, this navigable underground lake nestles in the hillside between 30 and 70 meters below the vineyards. With a length of 300 meters, it is the largest natural, navigable underground lake in Europe. As the cave is completely submerged, all visits are made aboard rowing boats for up to 40 people. In complete silence, our multilingual guides will take you on a tour of this fascinating world. During a 30-minute guided tour, you’ll glide over the clear waters of the lake and learn to decipher its mysteries. We look forward to your next visit.