Avenc Cp.4

An opening of 1.5 x 0.8 metres gives us access to a 25-metre pit divided into two sections by a ledge. A 20-metre route among blocks leaves us at the small opening of an 11-metre pit. At its base, a long and laborious dig allowed the discovery of a new pit that, at its midpoint and making a lateral shift, leaves us on a ledge at elevation -74.5. Continuing down the pit, one reaches 102 metres of depth with no further continuation. A dig at the opposite end of the -74.5 ledge allows descending a small 7-metre pit until reaching the entrance of another pit, this one 22 metres. Again a dig facilitated entry into a narrow 10-metre pit, at the bottom of which the point of maximum depth is reached. In the absence of survey data provided by the authors, we have estimated that the total route of the cavity may be around 250 metres at minimum.