Grotte e abissi nell'unità geologica Valls d'Hostoles i d'en Bas

The Valls d'Hostoles i d'en Bas are a unit of the Serralada Transversal formed by sandstones and volcanic terrain of the Garrotxa. The catalogue records 36 cavities, among them 25 caves and 11 pits, with a total length of 1355 m and a maximum depth of 40 m. The lithologies represented are sandstones, limestones, travertines, schists and marls.

The longest cavity is the Cavorca de Falgars, with 251 m, which is also the deepest, with 40 m of vertical drop; it was explored and surveyed by the Grup d'Espeleologia de Badalona between May 1994 and January 1995. It is followed by the Avenc de Can Roca Roja Nº2, of 149 m, and the Cova de la Carrera, of 134 m. Other notable cavities are the Avenc de Can Roca Roja Nº1, of 111 m, and the Cova de Roca Lladre, of 80 m.