Grotte di Sant Pere de Ribes

Sant Pere de Ribes, a municipality in the Garraf, has 13 inventoried cavities: 4 pits and 9 caves. Together they total 307 m of passage and reach a maximum depth of 15 m. Limestone is the dominant lithology (12 cavities), with a single cavity in dolomite.

The longest cavity is the Cova Negra, with 69 m of passage at the riera de Jafre (Garraf), known since time immemorial and excavated in 1956. It is followed by the Avenc de la Gelasa I, with 53 m, explored around 1970 by the GET de l'AE Talaia, and the Coves de la Cuneta, with 45 m, on the BV-2111 road from Sant Pere de Ribes to Olivella.

As for depth, the Avenc de la Gelasa I reaches 15 m; the Avenc dels Arcs, a sinkhole of the riera de Jafre, is penetrable to 14 m; and the Avenc de la Gelasa Ii reaches 10 m, with widths between 0.5 and 1 metre. Other notable cavities are the Avenc del Mas de Mossèn Alba, with 25 m of passage and with material from the Late Bronze Age and Early Roman Empire, and the Cova Negra, with 8 m of depth.