GR20 Corsica: Difficulty, Stages, and How to Plan It

Quick scan

As of 2026, the GR20 crosses Corsica's mountainous spine from Calenzana in the north to Conca in the south, roughly 180-190km taking 15-16 days for most hikers who walk one official stage per day (le-gr20.fr, "Profile & Stages", retrieved 2026-07-28). It is widely rated one of the toughest long-distance trails in Europe: rocky scrambling, exposed ridgelines, and chain-assisted sections in the north, with refuge bookings now mandatory on the official PNRC platform. Most first-timers do better hiking a shortened "half GR20" than attempting the full crossing untested.

• Full length is about 180-190km over 15-16 stages north to south, though many stages can be split or combined (le-gr20.fr, retrieved July 2026).
• The northern half (Calenzana to Vizzavona) is significantly harder than the south, with scrambling, scree, and chain-assisted rock sections.
• Refuge and bivouac reservations are mandatory on the official PNRC platform (pnr-resa.corsica), not optional add-ons (Fédération Française de la Randonnée, retrieved July 2026).
• Season runs mid-May to early October, with snow lingering on high passes into June some years (PNRC via corse-experience.com, retrieved July 2026).
• A "half GR20" (Vizzavona to Conca or Calenzana to Vizzavona) is a legitimate way to do it if 15-16 consecutive days of mountain hiking isn't realistic.
• This is not a first long-distance trek: if you haven't done multi-day mountain hiking with a loaded pack before, build up on something gentler first.

The GR20's difficulty is real, not marketing hype

The GR20 earns its reputation as one of the hardest waymarked long-distance trails in Europe, and it is not exaggerated marketing copy. This is a mountain trek requiring scrambling with hands as much as walking, on granite slabs, scree fields, and exposed ridgelines, not a flat rural footpath with a tough name.

The trail is split into a northern and southern half at Vizzavona, and the two feel like different hikes. The northern section (Calenzana to Vizzavona) is the harder of the two: steeper ascents and descents, more exposed scrambling, and chain-assisted passages where the rock is too steep or smooth to climb unaided (Much Better Adventures, retrieved July 2026). The southern half (Vizzavona to Conca) is still a serious mountain trek with long days and real elevation gain, but it's generally less technical and more forgiving underfoot.

One passage deserves a direct note because outdated blog posts still describe it incorrectly: the Cirque de la Solitude, once the trail's most infamous chained scramble, is no longer part of the official route. After a fatal storm and rockfall killed seven hikers there in June 2015, the old chains and ladders were removed and the waymarked GR20 was permanently rerouted onto a higher variant over the Bocca Crucetta, avoiding the original passage entirely. The historic route is not marked and not recommended. That said, other chained and ladder-assisted sections remain on the current official route in the north, so hands-on scrambling with exposure is still a normal part of most days up there.

Who should not attempt the full GR20 as a first long trek: anyone without prior multi-day hiking experience carrying a loaded pack, anyone uncomfortable with exposed scrambling and a head for heights, and anyone hoping for a scenic stroll between villages. If that describes you, this isn't the trail to learn on. Build fitness and technical comfort on a gentler multi-day route first, see our hiking in France guide for options across difficulty levels, or consider the GR10 across the Pyrenees as a longer but generally less technical alternative.

North to south or south to north?

Most hikers walk Calenzana to Conca, north to south, and that's also the direction most guidebooks, waymarking conventions, and shuttle logistics are built around. The practical argument for this direction is straightforward: it front-loads the hardest, most technical terrain (the northern half) while legs and lungs are freshest, then eases into the comparatively gentler southern half as fatigue accumulates over the second week.

Walking south to north (Conca to Calenzana) is possible and some experienced hikers prefer it, reasoning that it saves the psychologically toughest terrain for last when trail fitness has peaked. Either direction uses the same refuges and the same official stage numbering, just read in reverse, so logistics don't meaningfully change based on direction. For a first attempt, north to south remains the more common and arguably more sensible choice.

The GR20 route across Corsica from Calenzana to Conca

francetravel.wiki

• Calvi
• Corte
• Ajaccio
• Bastia
• Porto-Vecchio

Stage count, and how to shorten the trek

The official route is broken into 15-16 numbered stages depending on which variants you take, each running roughly 5-20km, with cumulative elevation gain and loss that outweighs raw distance as the real measure of difficulty (gr20-infos.com, retrieved July 2026). Walking one official stage per day end to end takes most hikers about 15-16 days, though fit, fast parties sometimes combine short stages to finish faster, and slower parties commonly split the longest, most exhausting days into two.

Not everyone has 15-16 consecutive days for a single trek, and the GR20 doesn't require that commitment to be worthwhile. The trail's natural halfway point at Vizzavona has road and rail access (the Ajaccio-Bastia line stops there), which makes it a clean split point for a shortened "half GR20":

• Northern half (Calenzana to Vizzavona): roughly 7-8 days, the harder and more scenic half, with most of the scrambling and chained sections.
• Southern half (Vizzavona to Conca): roughly 7-8 days, still demanding but less technical, ending near the coast close to Porto-Vecchio.

Section	Terrain / difficulty	Notable feature
Northern half (Calenzana to Vizzavona)	Harder: steeper ascents and descents, more exposed scrambling, chain-assisted sections; roughly 7-8 days	Most of the trail's scrambling and chained passages
Southern half (Vizzavona to Conca)	Still demanding but generally less technical and more forgiving underfoot; roughly 7-8 days	Ends near the coast close to Porto-Vecchio

Doing one half is a completely legitimate way to experience the GR20 without committing two full weeks or the cumulative fatigue of the entire crossing, and it's often the smarter choice for a first attempt.

When should you go, and what about snow?

The GR20 refuge season runs from mid-May to early October, matching when the Parc Naturel Régional de Corse (PNRC) staffs and opens its refuges along the route (PNRC via corse-experience.com, retrieved July 2026). Outside that window, refuges are unstaffed or closed and conditions on the high passes turn genuinely alpine.

Snow is the detail most trip planners underestimate. Corsica's interior peaks sit around 2,000-2,700m, and snow patches routinely linger on the highest passes and north-facing slopes well into June, some years later. Early-season hikers (May, early June) should expect to cross snow, may need microspikes on certain passes, and should have the experience to judge when a snow-covered scramble is unsafe to attempt. Mid-July through August is peak season with the most reliable conditions but also the busiest refuges and the hottest daytime temperatures on exposed rock. September offers a good balance: reduced crowds, generally stable weather, and snow long gone from all but the very last patches.

How do refuge bookings and reservations work?

This is the single biggest logistical change hikers need to plan around: refuge and bivouac reservations along the GR20 are now mandatory, booked exclusively online through the official PNRC platform at pnr-resa.corsica, with payment by card at time of booking (Fédération Française de la Randonnée, retrieved July 2026). Turning up at a refuge without a reservation and expecting a bunk or even bivouac space is no longer a reliable plan.

Popular refuges fill up quickly once the booking window opens for the season, so reserving as early as possible, ideally as soon as the platform opens, matters more than it once did. Refuges offer dormitory bunks, and most also sell half-board meals; bivouac (camping) spots near refuges are cheaper but still require the same mandatory reservation. Given how central this booking step now is to actually walking the trail, treat it as the first planning task, before flights, before gear, before anything else.

What gear do you actually need for this terrain?

The GR20's terrain is what separates its gear list from a standard hiking-in-France packing list. Beyond the usual multi-day trekking kit (proper boots, a well-fitted pack, layers for temperature swings between valley heat and ridge wind), plan specifically for:

• Sturdy, ankle-supporting boots with genuine grip, not trail runners; the granite slabs and scree punish soft soles.
• Via-ferrata-style gloves for the chain-assisted sections, where bare hands on hot or sharp rock and metal get uncomfortable fast.
• A headlamp and an honest turnaround time, since several stages are long enough that hikers who start late get caught on exposed terrain after dark.
• Trekking poles that collapse or stow easily, useful on the approach and descent stages but a liability (better strapped to the pack) during hands-on scrambling.
• Layers for real temperature swings: valley floors can be genuinely hot in July and August while exposed ridges catch wind and cold fast, especially early or late in the season.
• Microspikes if hiking in May or early June, when snow patches on the highest passes are still likely.

This is not a trail where ultralight minimalism pays off if it means skimping on grip, protection for hands and ankles, or a margin for weather.

How does the GR20 fit into a wider Corsica trip?

The GR20's two endpoints sit far from each other and from Corsica's main airports, so getting to and from the trailheads is its own logistics puzzle, separate from the trek itself. Calenzana, the northern trailhead, is a short bus or taxi ride from Calvi, itself reachable by air or the island's internal narrow-gauge train from Ajaccio or Bastia. Conca, the southern trailhead, sits inland from Porto-Vecchio in the southeast, generally the least convenient corner of the island to reach directly, so most hikers finishing there connect onward via Porto-Vecchio or Figari airport.

Because neither endpoint is a natural first or last stop on most Corsica itineraries, it's worth reading the island's broader logistics before locking in dates. Our Corsica travel guide covers getting to the island by ferry or flight and choosing a base; north or south Corsica helps decide which half of the island to prioritize around the trek; and Corsica without a car is essential reading since most GR20 hikers don't want to manage a rental car sitting idle at a trailhead for two weeks. If you're weighing the GR20 against a shorter, non-hiking Corsica trip, how many days in Corsica lays out the tradeoffs for a first visit versus a dedicated trekking trip.

For a wider view of France's long-distance trekking options and how the GR20 compares in difficulty to routes elsewhere in the country, see the hiking in France guide. If the GR20's technicality sounds like too much but you still want a serious multi-week trek, the GR10 across the Pyrenees covers similar distances with generally less exposed scrambling.

Sources

• le-gr20.fr, "Profile & Stages", retrieved 2026-07-28
• Fédération Française de la Randonnée, "GR20: ouverture des réservations pour la saison 2026", retrieved 2026-07-28
• corse-experience.com, "Refuges du GR20: la nouvelle plateforme PNRC change la donne pour 2026", retrieved 2026-07-28
• Much Better Adventures, "GR20 Corsica Guide: 15 Stages", retrieved 2026-07-28
• gr20-infos.com, "Stages", retrieved 2026-07-28

Frequently asked questions