St-Léonard's underground lake

In 1943, Jean-Jacques Pittard explored for the first time the mysterious cave of the underground lake.

Only in 1949 did the lake become accessible to the public. With a length of 300 m, a width of 20 m and a depth of 10 m, the underground lake of St-Léonard is the largest of its kind in Europe.

More than 100,000 tourists visit this exceptional natural wonder every year.

Multilingual guides take visitors on tours of the site aboard barges that can hold up to 50 people.

• Car parks for cars and coaches 150 m away
• Open every day from 19 March to 1 November from 9 am to 5 pm
• In June, July, August and September from 9 am to 5:30 pm
• Snack-Bar terrace at the very entrance to the grotto
• Guided tours available in four languages: French - English - German - Italian
• Duration of the tour: 30 minutes
• Last guided tour: 5:30 pm