Large landslide hits Cirque du Fer-à-Cheval, Haute-Savoie, France
A massive landslide released at least 12 000 m3 (424 000 ft3) of rock from 1 300 m (4 265 feet) altitude at Cirque du Fer-à-Cheval in Sixt-Fer-à-Cheval, Haute-Savoie, France, at 11:30 LT (09:30 UTC) on September 6, 2025. Expert analysis suggests the actual volume may reach 30 000–40 000 m3 (1.1–1.4 million ft3), making the event exceptional for this sector.
A large landslide struck the Méridienne–Pas Noir sector of the Cirque du Fer-à-Cheval in Sixt-Fer-à-Cheval, Haute-Savoie, releasing at least 12 000 m3 (424 000 ft3) of limestone from a cliff at 1 300 m (4 265 feet) at 11:30 LT (09:30 UTC) on September 6.
Blocks traveled downslope into the Giffre Valley floor, producing a broad dust plume visible from surrounding viewpoints. While no injuries took place, authorities immediately closed the impacted sector to visitors and maintained access restrictions pending stability assessment.
While initial estimates place the detached volume near 12 000 m³ (424 000 ft³), geomorphologist Ludovic Ravanel (CNRS / Université Savoie Mont Blanc) said the true figure may be substantially higher, perhaps 30 000 to 40 000 m3 (1.1–1.4 million ft3), and described the collapse as exceptional for this altitude.
Ravanel added that the cirque’s limestone walls remain unstable due to freeze–thaw cycles, structural discontinuities, and ongoing erosion and warned that the short-term hazard is elevated. He advised keeping strict access restrictions in place until the slope can be fully reassessed.
The Cirque du Fer-à-Cheval is a popular alpine destination, known for its steep limestone cliffs and numerous waterfalls. The same geological features that draw visitors also make the area prone to rockfalls, which at times force temporary trail closures.
References:
1 Un important éboulement provoque la chute de 12 000 m³ de roche en Haute-Savoie – Le Parisien – September 6, 2025
2 Haute-Savoie : 12 000 mètres cubes de roche se détachent d’une falaise, aucun blessé – TF1 Info – September 6, 2025
3 Spectaculaire éboulement à Sixt-Fer-à-Cheval : 12 000 m³ de roches dévalent la montagne – Actu Forces de l’Ordre – September 7, 2025
4 « Peut-être 30 000 ou 40 000 mètres cubes » : l’éboulement au Cirque du Fer-à-Cheval est d’une ampleur exceptionnelle – France Bleu – September 7, 2025
Featured image: Landslide at Cirque du Fer-à-Cheval, France on September 6, 2025. Credit: Seb de la Montagne
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