Avenc d'en Viumala

The entrance is nearly horizontal, formed at the intersection of a joint (N10O) and the bedding planes. It forms two passages, one upper and one lower, which lead to a shaft down which one descends to – 39 metres and then a sequence of shallow shafts (3-4 metres) reaches the point of maximum depth (elevation – 47). It is a pit of great development in a N-S direction but very narrow in the E-W direction. It has small secondary galleries always of rectilinear intersections, very similar to that of the nearby Cova de les Rondes. Its genesis can be perfectly appreciated in the E-W section; it is nothing more than a joint opened a few metres, the part communicating with the exterior being covered with blocks.

The first speleological visit was carried out on 15 September 1907 by Faura i Sans, Puig and other companions of the Club Muntanyenc. On this occasion they could only reach the mouth of the shaft, which they sounded but considered its exploration dangerous for lack of suitable equipment. It is not until 1932 or 1933 (we do not know the exact date) that a group of members of the Club Excursionista de Gràcia and of the Ateneu Igualadí explore it and reach the bottom of the shaft.

There is a total absence of erosion forms, with graviclastic processes everywhere.