The explorers in 1977 started on the descent of a fine 60m pitch of constant shape, slightly sloping, Puits Zorglub. At the bottom of this is the only chamber of the cave : the Salle Galactique. Here the cave splits into two routes, the active and the fossil.
Downstream from the chamber a drop leads to a small chamber among boulders, the Love Nest. (No idea who ventured to call it this). Between the boulders a 20m pitch opens, immediately followed by a 25m pitch. In fact, the last 25m of descent drops between the walls of an immense aven to land on a flat gravel floor. A diagonal chimney leads to a trickle of water.
A fissure marks the start of the Méandre Anti-Matière, where one immediately rejoins the underground stream. This has an average flow of two litres per second but quite rapidly increases to 10-15 litres per second in flood. The first part of the meander is straight and interrupted by 3 small pitches and two drops. At the top of the first, in the roof, is the connection with the fossil system. Quickly, the meander becomes less amenable: high and narrow, it is plastered with mud (the anti-matter) which makes progress quite arduous. Three pitches of 5, 14 and 10m punctuate progress. This last, followed by a drop of 3m, gives access to a section of passage blocked by clay. At the end of this, the stream disappears into a fissure with tight impenetrable bends.
The main passage continues ahead as a quite large fossil branch. After some 50m, the draught goes into an earthy hole, the start of a big pitch of 70m in several stages, the Puits du Centaure.
Halfway down, the pitch is rejoined by the stream which is avoided by a parallel fossil shaft. There immediately follows another pitch of 55m, the Puits du Fond des Ages, totally wet and characterised by an elliptical cross-section and constant slope. At the bottom, the water is engulfed by a fissure about three metres long, followed by a tight meander which has not been pushed. This is the deepest point : -565m.
Upstream from the Salle Galactique, a window some metres high gives access to a good-sized passage (3x3m on average), the Méandre des Petits Hommes Verts (the Little Green Men's passage). One comes up against a climb of 3m at the base of which the trickle of water is lost into a meander cut below the fossil passage (see below). After a narrowing and a climb, the passage ends in boulders between which it is still possible to penetrate for a dozen metres.
Back in the meander below the fossil passage: this ends at the Puit de la Comète (discovered by the Gaumais), a 60m pitch, spray-lashed in its lower part by Le Pipi (the wee-wee). At the base of this pitch is the beginning of the Méandre des Mutants. This is a passage for masochists par excellence: low and tight, gear gets caught everywhere. It ends in a series of climbs and a 30m pitch joining the active system.
See reference 78-2008 for Geology and Meteorology.