Corsica & the GR20: Europe's Hardest Long-Distance Trail
The GR20 (Grande Randonnée 20) is widely regarded as the toughest long-distance hiking trail in Europe — 180 km of granite scrambling across the mountainous spine of Corsica from Conca in the south to Calenzana in the north, with relentless ascent and descent on boulder-strewn, sometimes exposed terrain.
It is not a gentle walk. The northern half in particular involves hands-on scrambling, route-finding over slabs, and long days between basic refuges. The reward is some of the most spectacular and wildest mountain scenery in the Mediterranean.
This guide covers the two halves, the refuge system, the short season, and an honest assessment of the fitness and experience required.
The Northern and Southern GR20
The northern half (Calenzana to Vizzavona, ~100 km, 7–9 days) is the harder, more spectacular section — granite cirques, exposed scrambling, and the famous Spasimata slabs and Cirque de la Solitude (check current conditions; sections have been rerouted after rockfall).
The southern half (Vizzavona to Conca, ~80 km, 5–6 days) is lower, forested and gentler, though still demanding. Many walkers split the trail or walk only one half. Vizzavona is the midpoint, accessible by the island's railway.
Refuges and Season
The GR20 is hut-to-hut, with PNRC (Parc Naturel Régional de Corse) refuges spaced roughly a day apart. Refuges must be booked in advance for July–August; tent pitching is limited to designated areas near each refuge.
The season is short: June to September. Snow blocks the high sections until late June; by October the refuges close and weather becomes unstable. July–August is hot and busy; June and September are quieter and often ideal.
Fitness and Preparation
The GR20 demands genuine mountain fitness and a head for heights. Expect 6–10 hour days with sustained scrambling, boulder fields and exposed slabs, especially in the northern half. Train on rough, steep ground with a full pack, and practise confident scrambling before you go. Trekking poles help on the descents but are often stowed for scrambling sections.
Carry full waterproofs, warm layers, a head torch, a small first-aid kit and sturdy boots with good grip. Refuges must be booked in advance for July–August; tent space is limited to designated pitches near each refuge. Start early each day to avoid the afternoon heat and the common thunderstorms, and check current conditions — sections have been rerouted after rockfall.
Frequently asked questions
- How long is the GR20? Approximately 180 km over 12–15 days from Conca to Calenzana (or vice versa), with about 10,000 m of cumulative ascent. It is considered the hardest long-distance trail in Europe.
- Is the GR20 dangerous? It involves sustained hands-on scrambling and exposed terrain, especially in the northern half. It is not technically a climb, but it demands a head for heights, good fitness, and mountain experience. Sections have been rerouted after rockfall — check current conditions.
- When is the best time to hike the GR20? June to September. Snow blocks the high sections until late June; July–August is hot and busy; September is quieter and often ideal. Refuges close by October.
- Do I need a guide for the GR20? Not legally, but it is recommended for less experienced mountain walkers. The northern half requires confident scrambling and route-finding. Refuges must be booked in advance.
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