The volcanic nature of the environment also translates into a lake, the Issarlès Lake, coiled up in an ancient crater, as well as in the form of a waterfall named "le Ray-Pic". The waterfall is surrounded by basaltic organs and at about 30-metre high, it is one of the longest lava flows in France. Beware though, swimming in the waterfall is not allowed! The path leading to the waterfall has been recently adjusted to allow for a safe stroll, alternating between natural pathways and stairs. In places where the ground is steeper along the path, hikers can use a rope for more support.