Grotte della Pallars Sobirà

Pallars Sobirà contains 111 recorded cavities: 71 pits and 40 caves, totaling 8077 m of passage. The maximum depth reached is 320 m. The dominant lithologies are limestones (93), accompanied by schists (5), conglomerates (6), gypsum (3), sandstones (2), slates (1) and granites (1).

Among the longest cavities are Avenc Gran d'Aulà, with 1530 m, and Cigalera de l'Obaga de Baleran, with 900 m. As for vertical drop, Cigalera de l'Obaga de Baleran reaches 320 m, followed by Avenc Gran d'Aulà with 155 m and Avenc de la Tindarella with 116 m.

Avenc Gran d'Aulà, in Alt Àneu, at the port d'Aulà (2262 m), was discovered in July 1975 by the SS Plantaurel and the ASMP, and in 1984 the maximum depth was fixed at the -155 level. Cova Nº1 del Barranc de Moredo, with 764 m of passage, was discovered and explored in August 1979 by the S.S. Plantaurel and completed in September 1991 by the SIS del CE Terrassa.