Gouffre Jean-Bernard

In the upper part of the Vallon des Chambres, Gouffre B19 at an altitude of , which had been discovered in 1968, was explored down to . In 1975, winter expeditions began. The elevation was exceeded on 4 January and at , the Salle des Crêpes was discovered two days later, marking the end of explorations for that year. The Gouffre B19 was connected to the network on the first of November, giving a system depth of .