Grotte e abissi nell'unità geologica Serra de Sant Gervàs

The Serra de Sant Gervàs is a limestone range of the Prepirineu, between Pallars and Ribagorça, entirely karstic. It contains 18 cavities: 12 caves and 6 pits, with a total passage of 567 m and a maximum depth of 40 m.

Among the most notable cavities are the Cova del Sanat, with 102 m of passage and an entrance about 90 m high by 23 m wide; the Cova Fosca de Sant Gervàs, of 57 m; the Graller del Portús, a pit 40 m deep with an entrance of 8x5 m in a doline, explored since 1966; the Mina Inferior de la Canal, of 51 m; and the Graller de Sant Roc, with a drop of 35 m, an entrance of 8x3 m and a shaft of 28 m.