Lac Souterrain de St-Léonard

The subterranean lake of St-Leonard

The subterranean lake of St-Leonard is located along the Rhone valley, between Sion and Sierre in the heart of the Swiss Alps.

With a length of around 300 meters this is the largest natural underground lake in Europe.

During a 30 minute boat trip on the crystal clear water, you will enjoy the peace of this amazing place while your guide explains  all sorts of fascinating details about the origin and the history of the underground lake.

Private tours, concerts and special events available on request.

Lac Souterrain de St-Léonard

Rue du Lac 21
1958 St-Léonard

[email protected]

N 46° 15 ‘ 24.19‘‘ E 7° 25‘ 33.42‘‘

Opening times

Open daily from mid-March to early November

From 10AM till 5PM daily


In July and August from 9AM till 5.30 PM

Lac Souterrain de St-Léonard