The fourth stage leaves Saint-Chaffrey through the Guisane valley and climbs via Le Monêtier-les-Bains to Col du Lautaret. The road gains height steadily, with views towards the Écrins and the high slopes above the Briançonnais. At Lautaret, the route turns onto the road to Col du Galibier. The scenery becomes harsher here: fewer buildings, almost no trees, wide bends and open rock faces up to the pass. From Galibier, the route descends to Valloire, then continues over Col du Télégraphe into the Maurienne valley. After Saint-Michel-de-Maurienne and Modane, the road rises again towards Haute Maurienne. Before Termignon, the final kilometres pass close to fortifications, limestone walls and the edge of the Vanoise mountains.