The name 'Roches du Diable' translates to 'The Devil's Rocks,' stemming from local folklore regarding the jagged, chaotic formation of the granite.
The Ellé River, which carves this valley, serves as the natural boundary between the Morbihan and Finistère departments.
The granite outcrops here are part of the Armorican Massif, one of the oldest geological foundations in France.
The site experiences significant water level variations, with the river turbulence intensifying noticeably after heavy rainfall.
The narrow gorge created by these rocks provides a specific microclimate that supports dense, moisture-loving riparian flora.
Les Roches du Diable is a chaotic field of large granite boulders situated in the narrow, steep-sided valley of the Ellé River. The site features river water flowing forcefully through a labyrinth of rock formations, some reaching significant heights. It is a protected natural site characterized by its rugged topography and unique geological composition. The landscape is a product of the river's erosion over millennia, creating a stark contrast to the surrounding forested hills of the Finistère region. Footpaths wind along the riverbank, offering views into the ravine where the water channel narrows dramatically. It is a popular destination for hikers exploring the local greenways of Guilligomarc'h. The site is open to the public year-round without gates or entry requirements.
The wooden footbridge and viewpoints overlooking the tightest section of the river gorge.
Wear sturdy, closed-toe hiking shoes with good grip, as the granite surfaces are often wet and extremely slippery.
Bring a waterproof shell or jacket, as the narrow gorge traps spray and humidity regardless of the general weather.
Check local river flow reports if visiting after significant storms, as high water levels can obscure parts of the trail.
Attempting to cross the river by jumping between rocks, which is dangerous due to current strength and smooth stone surfaces.
Stay on marked trails to prevent erosion and do not attempt to scramble on the wet rocks, which are prone to moss buildup.
