Grotte della Val d'Aran

The Val d'Aran has 70 catalogued cavities: 16 caves and 54 pits. Together they total 8,512 m of passage and reach a maximum depth of 571 m. As for lithologies, limestone predominates (53), followed by marble (9), granite (4), slate (2) and sandstone (2).

The Sistema de la Bargadèra, in Escunhau, Vielha, is the cavity with the greatest vertical drop in Catalonia: it links the avenc de la Bargadèra and the horat des Lòses (CE-6), with a vertical drop of -571 metres, and has 2,100 m of passage. Other notable cavities are the Horat Der Uelh Deth Tor, a pit 169 metres deep explored since 1977 with 1,718 m of total passage, and the Sistema de Sarrahèra, an underground traverse with a vertical drop of 102 metres accessed via the Cauva de Sarrahèra and the Horat de Sarrahèra.

The Horat Der Unhòla is a large karstic depression and sinkhole with a cavity more than 200 m deep, which includes the Hilat Bernard Magos (T-2) and the Hilat era Ansa dera Caudèra, discovered in 2018. Also listed are the Cigalèra Deth Bacivèr, 163 m deep in Naut Aran, discovered in 1978 and explored and surveyed by the ERE-CEC in 1982, and the Horat Deth Bo, a 250 m underground stretch of the Malo river to the SE of the Plan de Beret.