Ultra Trail des Vallées

The Ultra Trail des Vallées is a 63-kilometer race with 1,800 meters of elevation gain held in Mesnil-Roc'h, in the Ille-et-Vilaine department, at the heart of inland Brittany. The longer version of the Trail des Vallées organized on the same territory, this ultra pushes endurance limits by offering an in-depth exploration of the deep valleys, sunken lanes, and bocage landscapes that make this little-known Breton countryside so special. Mesnil-Roc'h, a commune born from the merger of several villages between Dinan and Combourg, sits in a territory of gentle hills cut by rivers flowing down toward the Rance estuary and the English Channel.

The Ultra Trail des Vallées course unfolds its ribbon of trails through a dense network of ancestral sunken lanes — those paths bordered by tall embankments planted with oaks, beeches, and holly that constitute the most precious landscape heritage of inland Brittany. Over 63 kilometers, runners cross a mosaic of typically Breton landscapes: bocage meadows enclosed by living hedgerows, deciduous woodlands with undergrowth carpeted in ferns and wild bluebells in spring, damp valleys where streams flow between alders and willows, and agricultural plateaus offering broad perspectives over the surrounding countryside.

With 1,800 meters of elevation gain over 63 kilometers, the profile is that of a rolling ultra with an accumulation of short but incessant climbs and descents that test muscular endurance over time. The deep valleys of inland Brittany impose sometimes steep ascents on technical, muddy, and slippery trails, particularly in valley bottoms where the ground remains waterlogged for much of the year. Effort management over the distance, nutrition, and hydration become decisive factors, especially as Breton weather conditions — rain, wind, fog — can change rapidly and add an extra layer of difficulty.

The territory of Mesnil-Roc'h and its surroundings harbors a dense historical and cultural heritage. The Château de Combourg, an imposing medieval fortress with four towers, is inseparable from the memory of Chateaubriand, who spent a tormented and solitary childhood there, described in his famous Memoirs from Beyond the Grave. Menhirs and dolmens scattered across the countryside recall that this land was inhabited long before the Celts. Small rural chapels, sacred fountains, and granite calvaries punctuating the course bear witness to the depth of Breton spirituality, a singular blend of Christianity and pre-Christian traditions.

The Ultra Trail des Vallées stands as the premier ultra trail event in Brittany, proving that despite its modest altitudes, the region offers ultra trail terrain of remarkable difficulty and beauty. Its 63 kilometers through the valleys and sunken lanes of Ille-et-Vilaine represent a major endurance challenge where technical terrain, omnipresent mud, and a sawtooth profile wear down bodies as surely as high mountains. The welcome from volunteers and locals, imbued with legendary Breton generosity, transforms each aid station into a celebration: wheat and buckwheat crêpes, far breton cake, Guéméné andouille sausage, farmhouse cider, and chouchen mead warm the bodies and hearts of ultra trail runners. This race is a love letter to secret Brittany, the Brittany of sunken lanes and whispered legends.

Ultra Trail des Vallées is a 63 km trail race with 1,800 m of elevation gain, located in Mesnil-Roc'h, Ille-et-Vilaine. The next edition is scheduled for 4 October 2026.

Find all official information on the race website.