Grotte e abissi nell'unità geologica Massís de Bonastre

The Bonastre Massif, located in the Serralada Prelitoral, in the Baix Penedès, brings together 41 cavities: 19 pits and 22 caves. The whole totals 2376 metres of passage and reaches a maximum depth of 70 metres. It is a modest but characteristic karst, developed in dolomites (17), limestones (16), sandstones (7) and conglomerates (1).

Among the cavities most notable for passage length are the Cova d'Artús-forat del Vent, with 564 metres, and the Cova de Vallmajor, with 395 metres, known since ancient times and protected in 1998 as a World Heritage Site. Other notable cavities are the Cova Fonda, at 286 metres, and the Cova d'en Merla, at about 180 metres, known since the 13th century. As for depth, the Avenc de Vallmajor reaches 70 metres, followed by the Cova de Vallmajor, at 67 metres, and the Avenc de l'Arlà, at 63 metres.