A milestone in prehistoric finds, the Niaux cave is famous throughout the world. Its imposing porch dug into the cliff dominates the valley of Vicdessos from a hundred metres up.
The Niaux galleries form an underground complex covering several kilometres. They contain the most beautiful line drawings of prehistoric art, drawn when Magdalenian talent was at its peak (around 13,000 years).

In order to preserve the site, the tour is limited to the "Salon Noir", a natural rotunda 800 metres from the entrance. Its light, smooth limestone walls are decorated with bison, horses, ibex and red deer along with mysterious signs. All are painted black using charcoal or manganese. Some animals are marked with arrows, perhaps due to hunting rituals. Others are almost life-size. There is in particular a horse similar to the Pottok, which currently runs wild in the Basque Pyrenees.