Some chambers communicate with the surface since the roof had caved in. It was the case of “Barrenc” which is a collapsing hole that is as deep and nearly as wide as Padirac. It is situated a few hundreds of metres from the car park.
La Clamoux, disappearing into Cabresprine, comes from impermeable schistose massifs. It flows from the North to the South of the sides of the Pic de Nore, and as far as the Mediterranean. It is no more the unique river to disappear and converge at the underground resurgence of Le Prestil.
Water coming from the villages of Rieussac and Citou penetrates when in contact with limestones and contributes to East-West digging of underground circuits and the great Cabrespine system. This digging is all the more active because erosion combines with
chemical corrosion due to the acidity of waters flowing from schistose massifs. As we have already described, the work of the water in the underground environment can be very complex.
And the same system, as it is the case for Cabrespine system, can include caves, caverns, underground rivers or subterranean lakes at the same time.
The diagram below allows us to understand and interpret better the complexity of underground environments.