Tour du Mont-Blanc, Long-distance hiking trail in France, Italy, and Switzerland

The Tour du Mont Blanc is a roughly 165-kilometre circular long-distance trail that circles the Mont Blanc massif through France, Italy and Switzerland. It passes through seven valleys, among them the Chamonix (Arve) valley, Montjoie, the Vallée des Glaciers, the Italian Val Veni, the two Val Ferret and the Trient valley. The highest points on any variant are the Col des Fours in France and the Fenêtre d'Arpette in Switzerland, both at 2,665 m.

The GR Tour du Mont Blanc was laid out in 1951 as a sporting mountain route. The following year, French GR trails covered nearly 1,000 km, and Jean Loiseau published Itinéraires de Corse. The official route has changed over the years, and several variantes now run parallel to it, some more demanding and some shorter with fewer viewpoints.

The route crosses three countries, so hikers pass from French-speaking Chamonix through Italian-speaking Valdigne to the Swiss Valais, where German is also spoken. The GR5 long-distance path shares part of the way between the Brévent summit and the Col de la Croix du Bonhomme. The annual Ultra-Trail du Mont-Blanc runs the whole circuit, with winners finishing in about 18 hours for men and 22 for women.

The best hiking conditions occur from late June through September when passes are free of snow and mountain huts are open. Hikers should prepare for rapid weather changes and carry warm clothing along with rain gear, since temperature and wind can shift quickly at higher elevations.

The route passes through all Alpine vegetation zones, from meadows with wildflowers to barren rock landscapes near the snow line. Hikers can walk through forests, alpine pastures, and rocky slopes in a single day, observing how plants and climate change with elevation.