The Auvergne region is a genuine open-air geology book and an archetype of volcanism. Its reliefs consist of multiple forms such as domes, cones, regular or half-moon craters, maars, or lava flows. The region was also shaped by varied geological layers and the process of continental fracture of the Limagne fault. Implanted south of the Chaîne des Puys, the Sancy stratovolcano presents the most mountainous landscapes and the sharpest reliefs in the region. It is particularly visible at the level of its ridges located between the nature reserves of Chaudefour valley and Fontaine Salée.