Grotte e abissi nell'unità geologica L'Anoia

The Anoia, in the Serralada Prelitoral, contains 60 cavities: 45 caves and 15 pits. The total recorded passage is 3183 m and the maximum depth is 47 m. The limestone and conglomerate reliefs of the comarca lie at the transition to the depressió Central.

Among the longest cavities are the Cova de les Rondes, with 552 m; the Coves del Mamut, with 537 m and an exterior fissure of 103 m; and the Coves de Castellolí, of about 450 m, excavated in Eocene limestones. Other notable cavities are the Cova de la Censada Nova, of about 265 m, and the small avenc M-15/15', of 142 m, located 13 m from the avenc M-14.

As for depth, the Avenc d'en Viumala reaches 47 m; the Cova de les Rondes, 37 m; the Cova de la Censada Nova, 33 m; the Avenc d'Ancosa, 26 m, begun in 1907 by the Club Muntanyenc; and the Coves del Mamut, 24 m. The lithologies present are limestones (30), travertines (22), dolomites (4), conglomerates (3) and sandstones (1).