Le Roc d'Enfer, Alpine summit in Bellevaux, France

Le Roc d'Enfer is a 2,244-metre mountain of the Chablais Alps in Haute-Savoie, on the communes of Saint-Jean-d'Aulps and La Côte-d'Arbroz. Its summit ridge carries two main peaks separated by a shallow saddle, the higher and broader one to the right, with a western shoulder, the pointe de Haute-Béné (2,215 m). Grey breccia and slate form steep faces and buttresses, snow patches hold in the gullies, and conifer forest covers the lower slopes.

This mountain formed millions of years ago when tectonic plates collided and thrust layers of sedimentary rock upward and over one another. It belongs to the Brèche nappe, a regional geological structure that took shape during the Alpine mountain-building period.

The name derives from the Latin Mons Maledictum, recorded as La Mont-Maudite on a 1580 map. Saint-Jean-d'Aulps residents called it roc d'Enfer, from inferus, "below", while Bellevaux and Vallon knew it as Pointe d'Oïl, Savoyard patois for "eagle peak". The Saint-Jean-d'Aulps form prevailed, and the summit's frequent thunderstorms reinforced the name.

The normal route starts from Saint-Jean-d'Aulps and passes the Refuge du Graydon. From Bellevaux a very steep couloir from the Col du Graydon joins the route, and from Praz de Lys the approach goes via the Col de Foron. The rock is brèche and sedimentary schist; paths are narrow and steep, slopes slippery when wet, and the summit attracts lightning with little shelter.

The summit ridge carries two main peaks separated by a shallow saddle, the right one slightly higher and broader, with an antecedent point, the Pointe de Haute-Béné (2,215 m), on the western crest. The mountain shelters golden eagles, chamois and mouflons. Its slopes feed three different river systems: the Brevon towards the Dranse and Lake Geneva, the Favets towards the Dranse de Morzine, and the Foron towards the Giffre and the Arve.