Grotte di Vielha e Mijaran

The municipality of Vielha e Mijaran, in the Val d'Aran, contains 44 recorded cavities: 6 caves and 38 pits. The group reaches a total length of 7166 m and a maximum depth of 571 m. The lithologies present are limestone (39), marble (3), slate (1) and sandstone (1).

Among the cavities, notable ones include the Sistema de la Bargadèra, in Escunhau, with 2100 m of length and a drop of -571 m, the greatest in Catalonia, which connects the avenc de la Bargadèra and the horat des Lòses (CE-6); the Horat Der Uelh Deth Tor, a pit 169 m deep and 1718 m long, a sinkhole for a stream coming from a tarn located some 250 m to the N, explored since 1977; the Sistema de Sarrahèra, an underground traverse with a drop of 102 m accessed via the Cauva de Sarrahèra and the Horat de Sarrahèra; the Horat Der Unhòla, a large karst depression and sinkhole with a cavity more than 200 m deep that includes the Hilat Bernard Magos (T-2) and the Hilat era Ansa dera Caudèra, discovered in 2018; and the Uelh Der Sescorjada, a vauclusian spring with a flooded conduit that reaches the -95 m level and a total length of 184 m, linked to the Horat der Unhòla by dye tracing.

Other notable cavities are the Horat d'Escunhau, a pit 101 m deep in the Bargadèra area, discovered and explored in 1997 by the Col·lectiu Escunhau (GIEG de Granollers and GREC de Barcelona).