In this magical place, the river disappears beneath a huge pile of boulders as you make your way upstream.
According to legend, the first man to live in Brittany, Boudédé, was responsible for creating the chaos of boulders. As he made his way along the path alongside the Forest of Duault he is said to have removed the stones from his boots and thrown them into the river!
Geologists explain the formation of the chaos of boulders by the effect of erosion in the natural fissures in the granite. The water made its way into the rock and enlarged the fissures, turning the boulders into a sort of sand - granitic sand - that was carried away by the current. Over time the rocks became increasingly worn and as their balance faltered, they collapsed and created the chaos of boulders that exists today. An interpretation path is due to be created between the Landes (moorlands) and the Gorges.