Wikipedia
Siebenhengste-Hohgant-Höhle
Siebenhengste-Hohgant-Höhle is a cave located in Switzerland, in the Canton of Bern north of Lake Thun, between the villages of Eriz and Habkern. The cave network formed in the Urgonian Limestone Formation ( Aptian age).
The cave was first explored in 1966 by the Club Jurassien, a speleology club from La Chaux-de-Fonds in the canton of Neuchâtel, Switzerland, when three of its 34 entrances were discovered. Explorations were later undertaken by many different regional caving clubs.
In 2010, it was the world's 11th longest cave, with a 154-km development. It is also the world's 22nd deepest cave at 1,340 m deep.