Gournier cave

The Gournier Cave is located near Choranche in the Vercors Massif in south-eastern France. The entrance is at an altitude of at the base of a cliff on the Presles plateau. It is one of the exsurgences (points at which an underground stream reaches the surface if stream has no known surface headwaters) of the Coulmes massif, and the cave is considered by many speleologists to be the most beautiful underground river in the Alps.