The Pierre-Saint-Martin abyss - the largest subterranean chamber in Europe, the Mas d’Azil cave, the Esparros abyss, the underground Labouiche river, and even the Lombrives, Betharram, Gargas, Niaux, and the Vache caves - the Pyrenees has many amazing geological surprises, some of which are unique in Europe.
Bathed by the sea and the ocean, as though baptised by the Gods, the Pyrenees has an incomparable wealth of natural subterranean treasures in addition to the peaks, canyons, cirques, and valleys. This wealth starts at the border between Soule and Béarn with the Pierre-Saint-Martin abyss. It is Europe’s largest underground chamber, and one of the biggest in the world, and recounts one of the greatest human adventures of the 20th century.


On the 13th of August in 1953 Georges Lépineux, Daniel Épelly and Jimmy Théodor reached the chamber which was later named the Verna, 734 metres deep.

The dimensions are amazing A diameter of 245 metres and 194 metres high - triple the height of the Notre-Dame towers!



In the Baronnies valley, the Esparros abyss is a unique crystal showcase. These aragonite concretions - gypsum or calcite crystals - form stone bouquets, as delicate and fragile as real flowers.
In Ariège, the Lombrives cave is the vastest in Europe. You can take an amazing 1,500-metre boat ride along the Labouiche underground river, 60 metres underground.
Not far away, the Mas d’Azil cave with immense galleries dug into the heart of the Plantaurel massif, is also a unique formation in Europe.
It was used as a refuge by the Magdalenians, and its name was given to a period of the prehistoric period, the Azilian.