Grotte della Maresme

El Maresme gathers 10 inventoried cavities: 8 caves and 2 pits. Together they total 169 m of passage and reach a maximum depth of 14 m. By lithology, 6 cavities develop in limestone and 4 in granite.

The most notable cavity is Avenc de les Aranyes, with 72 m of passage and 14 m of depth, in the Montnegre (Tordera, el Maresme), on the southern slope of the serra de l'Avetar, below a path from Can Soler to Hortsavinyà. It is followed in length by Cau de les Formigues (19 m), a small granite cavity in the Montcabrer with three entrances, near cova dels Tres Cercles, and Cavorca de Roca Andera (18 m), a cave in Tordera, in the Bagueny de Rupit, known since time immemorial and explored by the GE Badalona on 8-12-2001.

Other cavities are Cova del Pontet (11 m), a small granite tunnel in the municipality of Dosrius, and Forat Bufador (11 m), a small pit 5 m deep in Tordera, known since remote times and surveyed in 2007 by the G.E. Badalona.