Les Arcs de Saint-Pierre are geological curiosities located in the heart of the former Gallo-Roman village of resin workers (professionals who bleed into the pines to harvest the resin).
Nestled under a rock wall at the bottom of the village of Saint-Chély du Tarn, the Notre-Dame de Cénaret chapel, dating from the 12th century, sits near a spring leading to an underground lake. It's definitely worth the detour!
The Grotte de l'Homme-Mort was the site of the discovery of several skeletons dating back to 2000 BC. Some skulls even showed signs of healing trepanation. In short, the first rudiments of surgery.
There is a small, natural cave directly on the S1 hiking trail from Castlebourc to St. Enimie. It takes some climbing to explore this. Great view from a cave window.