An unusual stage, in search of the Napoleonic fortifications scattered between the Col de La Cou and Machaby. From here, after a visit to the Sanctuary of Our Lady of the Snows, the path descends through a chestnut forest to Arnad, guarded by the two Vallaise castles; visitors are greeted by the lovely Romanesque church of San Martino.

From the village of Donnas the route climbs the rocky ridge again, towards the village of Albard. From here it continues to climb towards the sunny meadows of the Col de La Cou, where it is still possible to see the remains of Napoleon’s fortifications dating from his attack and siege of Fort Bard. From here a magnificent view can be enjoyed towards Mont Avic and the peaks of Champorcher.

After passing the Arbénaz fortifications, the trail reaches the Fort of Machaby, today converted into a modern restaurant. From here the route arrives at the famous Sanctuary dedicated to Our Lady of the Snows, surrounded by chestnut woods. The decent continues until the village of Arnad comes into view, with the pink bulk of the Vallaise castle (currently being restored). Worth a visit is the delightful historic centre, with its towers and fortified houses, embellished by the splendid Romanesque church of San Martino, one of the Aosta Valley’s best-loved and most photographed churches.

Warning: the short section of the stage in Arnad, between the hamlet Costa and the hamlet of Ville, partially follows a portion of stage 22 Verres-Pontboset, therefore pay attention to the signs (the next stage no. 5 continues towards Challand-Saint -Victor: in Ville, from the bridge over the Pré stream, follow the signs for Col Vert)