Circuit des 25 Bosses
Mont Granier
Circuit des 25 Bosses vs Mont Granier: Intensity Score Comparison
Both routes share a similar overall intensity (48 vs 47). Depending on personal strengths, the challenge relies more on Circuit des 25 Bosses's technicality versus the physical output of the other.
Model-based (not a field report) · Evaluates overall route demand, not danger.
The 'Circuit des 25 Bosses' (The 25 Bumps) is located in the Massif des Trois Pignons, on the western edge of the Forêt de Fontainebleau. Originally established in the 1970s as a training ground for alpinists, this technical 16km loop remains one of the most demanding day hikes in the Île-de-France region. The trail requires hikers to cross 25 distinct sandstone ridges, involving frequent scrambling over boulders and navigating deep sandy paths. It is an intense physical challenge characterized by constant elevation changes and a unique ecosystem of maritime pines and white sand dunes. Note: Compiled from public sources — not a field report.
Standing as a massive limestone sentinel, Mont Granier in the Chartreuse Massif above Chambéry is the northern pillar of the region. Infamous for the catastrophic landslide of 1248, it features the highest vertiginous cliff face in France—a sheer 900-meter drop. The 11.3km circular hike via the Pas des Barres is an adventurous route that winds through steep beech forests before tackling the vertical limestone barriers with iron cables and rungs. The summit plateau offers a sweeping 360° panorama of the French Alps. Note: Compiled from public sources — not a field report.
Head-to-Head Metric Analysis
HikeMetrics Hazard Scale — Explanation
The HikeMetrics Hazard Scale is a proprietary 5-point classification system that evaluates hiking routes across five dimensions: physical demand, technical complexity, altitude exposure, weather risk, and rescue accessibility.
Unlike generic star ratings, the Hazard Scale is calibrated against altitude profiles, elevation gain per day, and logistical isolation factors — making it the most precise route classification system available.
Full Scale Documentation