The entrance is through an extremely narrow passage 25 centimetres wide and 3 metres long, leading to a small chamber where a pit of about 15 metres begins, of the spiral type, which opens into the ceiling of the main chamber. This chamber is of notable dimensions, as it measures 40 metres long with the presence of some large blocks fallen from the ceiling. At the SE end of the chamber and via a clayey ramp, the level of -26 is reached, and on the opposite side, almost below the entrance pit, is the point of maximum depth (level -27).

Lithogenesis is very important, but it only appears on the eastern walls of the pit and is represented by very varied forms.

On the E side there are some large pools of water with a very irregular level. It seems to be a swallow hole, today inactive, which through the entrance pit collected the waters of the nearby torrent until reaching an impermeable layer of marls and beginning the excavation of the chamber, later remodelled by an important clastic process.