Aiguille de la Grande Sassière, Mountain peak in Savoie and Aosta Valley, France and Italy

Aiguille de la Grande Sassière is a peak on the border between Savoie and Aosta Valley that rises to 3751 meters and presents different appearances from various viewpoints. Its notable north wall remains snow-covered much of the year, while the southern face drops steeply with exposed rock formations.

On 5 August 1860 the Englishman William Mathews, the Chamonix guide Michel Croz and a porter climbed the peak while searching for the fabled Mont Iseran. They found a cairn and fragments of a cross on the summit, and later learned that a Tignes resident, Bertrand Chaudant, had probably made the first ascent about fifty years earlier.

The summit marks the end of the Valgrisenche on the Italian side and commands the Val d'Isère on the French side, so it is read as a boundary point from both valleys. Its name, Grande Sassière, refers to the mountain and the glacier on its north face, and the Saut dam at 2,300 m gives access to the southern valley. The 1860 ascent by William Mathews, Michel Croz and a porter found a cairn and fragments of a cross, and they later learned that a Tignes resident, Bertrand Chaudant, had climbed it about fifty years earlier.

The summit is classed F and, when the ridge and summit pyramid are fully clear of snow, becomes a hike for experienced walkers; this happens only one to two months a year in summer. Crampons and an ice axe are still advised, as the schist often stays frozen even in summer. A car reaches the Saut dam at 2,300 m above the Grande Sassière nature reserve. The peak is also ridden by mountain bike, said to be the highest French summit reachable that way.

When William Mathews, Michel Croz and a porter reached the summit on 5 August 1860 while searching for the fabled Mont Iseran, they found a cairn and fragments of a cross. They later learned that a Tignes resident, Bertrand Chaudant, had climbed it some fifty years earlier.