Useful Information

Location: On the Weissenstein near Solothurn.
Open: All year Wed-Sat 8-22, Sun 7-18. Closed Easter and Christmas.
Nidlenloch I: All year.
Nidlenloch II: All year.
Fee: Entrance fee and deposit payable at the Restaurant Hinterweissenstein.
Nidlenloch I: Adults CHF 135.
Nidlenloch II: Adults CHF 195.
Classification: SpeleologyKarst cave TopicSacrifice Cave Sequan limestone (Malm).
Light: none, bring own.
Dimension: L=7.500 m, VR=418 m.
Guided tours: All year after appointment.
Bibliography: Zeitschrift für Mineralogie II. Band, Akademische Buchhandlung von J. C. B. Mohr, Heidelberg 1828.
Christian Preiswerk und Andres Wildberger (1997): Karst und Höhlen der Schweiz, Speleoprojects, Basel. ISBN 3-908495-05-9 (hardbound) bzw. ISBN 3-908495-06-7 (paperback)
W. Heiniger (1997): Erlebnis Nidlenloch, AGN und Speleo Projects, Basel. ISBN 3-908495-04-0
Address: Verwaltung Nidlenloch, Verenastr. 4, 4522 Rüttenen, Tel. +41-32-6235929, contact
Arbeitsgemeinschaft Nidlenlochforschung (AGN), Präsident: Rudolf Glutz, Hübeli, 4504 Solothurn, Tel. +41-32-6229024, contact
Alpinschule Tödi GmbH, Kirchhaldenstr. 25b, CH-8722 Kaltbrunn, Tel: +41-55-283-4382, Fax: +41-55-283-4385. E-mail: contact
Trekking Team AG, Lützelaustrasse 48, 6353 Weggis, Tel: +41-848-808-007, Tel: +41-41-390-4040, Fax: +41-41-390-4039, Cell +41-79-420-77-77. E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1828 first mentioned in Zeitschrift für Mineralogie II. Band, Akademische Buchhandlung von J. C. B. Mohr, Heidelberg 1828. Description of the first exploration by Franz Josef Hugi who discovered the first 350 m of the cave.
1868 survey by the engineer Moser who drew a vertical and horizontal projection.
1889 to 1891 several explorations by Forster und Rotschi.
1892 to 1909 more than 60 explorations led by Franz Held.
1909 the cave was the deepest known cave of the World with a depth of 396 m.
1937 and 1938 survey and map by F. Kormann und W. Kulli of 2122 m length.
1939 above map published.
1975 exploration by the new founded Arbeitsgemeinschaft Nidlenlochforschung (AGN) recommenced.
1979 the book Nidlenloch published by R. Vuille.
1985 third survey of the cave with 7.500 m cave length.
1997 booklet Erlebnis Nidlenloch by W. Heiniger published.


The Nidlenloch is an undeveloped cave, but it is open to the public. The first several hundred meters are rather easy to explore, but appropriate clothes, shoes and physical fitness are absolutely necessary. Please be careful and obey the rules of soft caving: leave no garbage and destroy nothing!

The cave is a huge an complex labyrinth. A good map is very helpful, and you should always visit the cave with the way back in mind. But the cave has many nice places and is fun to explore. Especially for children its an unforgettable adventure. And its possible to plan a tour according to the skills of the visitors. Several mountain guides offer guided tours, see the webpages below for more info.

This cave is possibly the most visited non show cave of Switzerland. Many parts are rather easy to visit and the cave has the atmosphere of a huge cave system. More than 5000 people visit the cave every year. But this has several bad consequences, like garbage, vandalism and a yearly rescue operation. On the other hand the cave works as a sacrifice cave: visitors interested in caves go to this well known caves, other caves of the areas remain undisturbed.

The cave lies in a layer of limestone from the Malm, the last period of the Jurassic. This layer was uplifted and inclinded during the formation of the Alps. The whole system follows this layer, which is rather impressive visible in the 3D visualization on the website below. The whole system strikes west-east and falls to the north.

The cave contains a certain amount of the white and soft SpeleothemMoonmilk. The comparison with dairy products is rather obvious. In this area of Switzerland the skimmings is called nidle. This is supposed to be the origin of the name.