Roc d'Hozières, Volcanic summit in Monts du Cantal, France

Roc d'Hozières is a phonolite dome with very steep walls, forming a rounded rock outcrop above the Mars valley on the boundary of Le Fau and Le Falgoux. Its bare grey face is split by vertical and diagonal cracks, with grass and low growth clinging to the ledges. Nearby stands the higher Roche Taillade (1,650 m), a trapezoidal summit that is easier to reach.

This volcanic formation was created roughly 6 million years ago during intense geological activity that shaped the entire Cantal range. The phonolite dome represents a remnant of the ancient volcanic processes that once dominated this part of Auvergne.

The name "bulle" (bubble) given to the 260-metre climbing route on the flanks refers to the rounded, bulging shape of the phonolite dome. The GR400 long-distance trail crosses the western slope, so walkers pass the foot of the climbing walls without scaling them.

The GR400 hiking trail runs along the western slopes and provides access points for both walkers and climbers throughout the year. The area remains reasonably accessible, though sturdy footwear and preparation are important given the changeable mountain weather.

The phonolite dome faces the Roche Taillade, a trapezoid-shaped summit that is higher at 1,650 m but far easier to reach. Climbers rate the routes on these steep flanks as difficult, among them the 260 m line known as "la Bulle".