Caves and potholes in el Pirineu Axial

The Pirineu Axial is the highest Pyrenean ridge, marking the border with France from l’Alt Àneu to the Val d’Aran. Unlike the limestone karst of the Prepirineu, geology here is dominated by granites, schists and other Paleozoic rocks, with a high-mountain relief shaped by Quaternary glaciers. The cavities cataloged here, scarcer than in the rest of the geographic units, often correspond to dissolution phenomena in the limestone bands interspersed within this Paleozoic basement.