Grotte e abissi nell'unità geologica Sant Salvador de les Espases - Serra de Rubió

Sant Salvador de les Espases - Serra de Rubió is a unit of the Serralada Prelitoral with 48 recorded cavities: 22 pits and 26 caves. The known total passage is 1012 m and the maximum depth is 20 m. The lithologies present include limestones (28), travertines (15), conglomerates (3) and sandstones (2).

Among the cavities most notable for passage are the Cova del Petrecó, with 130 m; the Baumes de les Illes, with 64 m; the Forat del Fum, with 62 m; the Escletxa del Pi, with 45 m; and les Esquerdes, with 40 m. As for depth, the Escletxa del Pi reaches 20 m, the Avenc del Clast 17 m, the Cova del Petrecó 16 m, the Avenc Rubricata 15 m and the Forat del Fum 14 m.

The group lies in conglomerate and limestone crags above the Llobregat, neighbours of Montserrat and Sant Llorenç. Several cavities were known or explored by the SIRE – UEC Olesa de Montserrat, such as the Escletxa del Pi around the year 1965, the Avenc del Clast in 1965 and les Esquerdes in 1985 and 1986.