How to Plan a GR20 Hike in Corsica: Refuges, Season, Water and Budget

TL;DR: The GR20 is a roughly 180 km, two-to-three-week traverse of Corsica’s mountains, and almost everyone who plans one badly gets tripped up by the same two things: refuge booking and water. As of the 2026 season, every overnight on the route — a refuge bed, a rented tent, or your own bivouac — has to be booked in advance on the official PNRC platform, wild camping is banned across the whole park, and conditions like wildfire closures can change parts of the route with only days of notice. This guide covers direction, season, booking, resupply, water, budget, safety, and where planning tools like traversly fit in once you’re actually on the trail and the plan needs to keep up.

The GR20 is a roughly 180 km high-mountain trail across Corsica, from Calenzana in the northwest to Conca in the southeast, and it is routinely described as one of the hardest waymarked long-distance trails in Europe. It isn’t hard because it’s badly marked or remote in the way a Scandinavian trail is remote — it’s hard because of what it asks of you every single day: loose rock, granite slabs, chains on the steep sections, and stages that keep climbing and dropping a thousand meters or more between a bed and the next one. Planning one well mostly comes down to getting a short list of things right before you leave home, because almost none of them can be fixed once you’re on the trail.

How long is the GR20, and how hard is it really?

The GR20 runs about 180 km with well over 10,000 meters of cumulative ascent, split into 16 official stages between Calenzana and Conca — though plenty of trekking operators group those into 15 daily stages by combining a short one with a neighbor. Most independent hikers take 15 to 16 days walking one stage per day; fast, fit parties who combine stages can do it in 10 to 12, and people carrying heavier packs or splitting the toughest stages in two often take closer to three weeks.

What makes it harder than the distance and elevation numbers suggest is the terrain itself: long sections of loose scree, exposed granite slabs polished smooth by traffic, and several stretches with fixed chains where you’re using your hands as much as your feet. None of it is technical climbing, but it’s a different category of trail from a well-graded alpine path, and it punishes people who show up expecting the latter.

Summary: Budget 15 to 16 days for the full traverse, and expect terrain — not distance — to be what actually slows you down.

Corsica is a beach destination — do you actually need alpine gear for the GR20?

Yes. Most people’s mental image of Corsica is the coast — turquoise water, beach towns, a Mediterranean holiday island — and that has nothing to do with the terrain the GR20 actually crosses. The trail spends almost all of its length above 1,500 meters, on exposed ridgelines and granite that can be wet, icy at the edges of the season, or lightning-exposed in a summer storm that built in twenty minutes. Pack and dress for it the way you would for any high alpine traverse — proper hiking boots, not trail runners, on the northern half’s rock; a real hardshell layer; a plan for what you do if weather catches you on an exposed stretch — not for a Mediterranean hike with a sea view.

Summary: The GR20 shares a coastline with Corsica’s beach resorts and nothing else — equip for a high alpine trail, not an island holiday.

Which direction should you hike: Calenzana to Conca, or the reverse?

Most guides describe the GR20 north to south, from Calenzana to Conca, and that’s the direction refuge capacity and most trekking-company itineraries are built around. The trail splits almost exactly in half at Vizzavona, a village with its own train station on the Ajaccio–Bastia line, which is why most people who only have time for one half start or end their trip there rather than at Calenzana or Conca.

Some experienced hikers deliberately go the other way, south to north, because the southern stages are gentler and let you build fitness and trail legs before the harder, more exposed northern section. The trade-off is finishing on the hardest terrain instead of easing out of it — worth weighing against your own fitness and how much margin you want left in your legs by the last few days.

Summary: North to south is the conventional direction and what refuge planning assumes; south to north front-loads easier stages at the cost of a harder finish.

Which half should you hike if you don’t have three weeks?

Splitting at Vizzavona is the standard answer if you only have a week or two, and the two halves are different enough in character that it’s more than a scheduling decision. The northern half, Calenzana to Vizzavona, is the cliffier, more mountainous side — jagged ridgelines, more exposure, and the terrain most GR20 photos are actually showing. The southern half, Vizzavona to Conca, gradually softens into wider pastures and rounder granite, and finishes among the Bavella needles, a landscape that feels closer to a US-style national park than the rest of Corsica.

If the high-mountain, chains-and-scree reputation is what drew you to the GR20 in the first place, walk the north. If you’d rather ease from rougher terrain into open pasture and finish somewhere that feels different from where you started, the south delivers that arc better.

Summary: The north is the harder, more classically alpine half; the south is gentler and ends in the more open, park-like scenery of the Bavella massif.

When is the best time to hike the GR20?

The realistic window is late June through mid-September, because that’s when the mountain refuges are staffed and open and the worst of the winter snow has cleared from the higher passes. July and August are peak season — hottest, busiest, and the months you need to book refuges the furthest in advance — while June and September are generally recommended as the best compromise of manageable crowds and stable weather, with the caveat that late-June stages can still carry snow patches at altitude in a heavy winter.

Summary: Late June to mid-September is workable; September usually offers the best weather-to-crowd trade-off, July–August the most reliable refuge and shop opening hours.

Do you have to book refuges on the GR20, and how does that work now?

Yes — booking is mandatory for every overnight in the park, with no walk-up option at the refuge desk. The Parc naturel régional de Corse (PNRC), which manages the trail and its refuges, runs all reservations through a single official platform, pnr-resa.corsica, and that applies whether you want a dormitory bed, a tent the refuge rents out and pitches for you, or a spot to pitch your own tent on the refuge’s designated bivouac area.

Bookings for a season typically open in January, and popular dates — especially July and August weekends — can fill without warning, so the practical approach is to lock in your stage-by-stage plan and book as soon as your dates are fixed rather than waiting. As of the 2026 season, PNRC’s published rates are in the range of €9–12 per person for a bivouac pitch, around €20 for a dormitory bed, and roughly €27–39 to rent a tent already set up (one or two people) — check the current prices on pnr-resa.corsica before you commit, since PNRC revises them each season and dates can’t be changed on-site with the warden once you’ve booked.

Summary: Every bed, rented tent, and bivouac pitch on the GR20 must be booked in advance on pnr-resa.corsica; there’s no booking at the refuge itself.

Is wild camping allowed on the GR20?

No — wild camping is banned across the entire Parc naturel régional de Corse, not only near the trail itself, and it’s an enforced rule with fines reported around €135 for pitching outside a designated area. The only legal option is the marked bivouac area attached to each refuge, and even that pitch has to be booked through pnr-resa.corsica ahead of time, the same as a dormitory bed.

This surprises a fair number of hikers who assume a lightweight tent buys them the flexibility to camp wherever they stop for the day. On the GR20 it doesn’t — your tent changes what you sleep in, not where you’re allowed to put it.

Summary: Camping is legal only in a refuge’s designated, pre-booked bivouac area — never wild, anywhere in the park.

How do you get to the GR20’s trailheads?

Corsica has four airports — Ajaccio, Bastia, Calvi, and Figari — plus ferry ports at Bastia, Ajaccio, and Propriano reachable from mainland France and Italy. Calenzana, the northern trailhead, is a short bus or taxi ride from Calvi; Conca, the southern trailhead, connects to Porto-Vecchio and Bonifacio the same way. If you’re only walking one half, Vizzavona is the easiest access point precisely because it’s on the Ajaccio–Bastia railway, not a bus connection you have to time around.

Bus and shuttle schedules on Corsica change between seasons and some years drop routes entirely, so treat any specific timetable you find — including this one — as something to reconfirm close to your dates rather than a fixed fact, ideally against FFRandonnée, France’s official hiking federation and the body that maintains GR waymarking standards nationally.

Summary: Fly or ferry into Ajaccio, Bastia, Calvi, or Figari, then bus or taxi to Calenzana or Conca — or use the Vizzavona train station if you’re only doing one half.

How does resupply actually work on the trail?

Refuges sell a limited range of food and snacks, and roughly every three to five stages the trail passes near, or a short detour from, a village or bergerie with a proper shop — but the gaps between them are longer than they look on a map, especially in the trail’s middle third. Most hikers carry two to four days of food between real resupply points and top up opportunistically at refuges along the way rather than relying on any single stage having what they need.

Independent GR20 resources that focus specifically on this — like Corsica Natura’s logistics breakdown — are worth reading stage by stage before you leave, since the exact shop hours and what’s actually in stock (this is rural Corsica, not a resupply town on the Appalachian Trail) vary by season and by whoever is currently running that particular bergerie.

Summary: Plan for 2–4 days of carried food between real resupply points, and treat refuge food as a supplement, not your main plan.

Is water a real problem on the GR20?

Generally, no — Corsica’s mountains have frequent streams and springs, and most stages cross water multiple times a day. The exceptions are real, though: a handful of stretches, particularly in the southern half in peak summer, run dry between refuges, and what’s flowing in June can be a trickle by late August. Treat any water you don’t take directly from a refuge tap, the same way you would on any mountain trail with grazing animals nearby.

Summary: Water is plentiful most of the route, but a few late-summer stretches genuinely run dry — check the stage-specific detail, not just the trail-wide reputation.

What happened to the Cirque de la Solitude, and does it still matter?

The Cirque de la Solitude, once the GR20’s most notorious chained passage, has been closed to the official trail since a 2015 storm and rockfall killed seven hikers there. The route has been permanently rerouted onto a variant that climbs via Pointe des Éboulis and descends to Bocca Crucetta before rejoining the main trail near Tighjettu — longer and higher than the old route, with some chained sections of its own, but not the exposed scrambling the original cirque required. If you’re reading an older account of the GR20 that describes the Cirque itself as part of the route, that description predates the reroute.

Summary: The Cirque de la Solitude is no longer part of the official GR20; today’s route uses a longer, less exposed variant around it.

What should you budget for a GR20 thru-hike?

Beyond flights or ferries, the recurring costs are refuge/bivouac fees (the €9–20+ per night range above, times 15–16 nights), food — refuge meals, resupply shopping, and whatever you carry in — and any bus or taxi transfers to and from the trailheads. People sleeping in their own tent and self-catering spend meaningfully less per day than those eating refuge half-board every night and renting equipment; either way, the trail itself has no entry fee beyond the mandatory overnight bookings.

Summary: Overnight fees are the one fixed, unavoidable cost; food and gear rental are where a GR20 budget actually varies person to person.

What are the main safety risks, and how current do you need to stay?

The terrain itself — loose rock, exposure on the chained sections, and sudden mountain-weather changes including lightning — is the baseline risk on any GR20 stage, and it’s why the trail rewards prior scrambling and multi-day backpacking experience rather than being a good first long trail. Beyond that, the risk that catches planners out is how quickly official conditions can change: wildfire risk closes sections of the park with days’, sometimes hours’, of notice during dry summers, and a closure can strand hikers at a refuge until the park reroutes or shuttles them around it, as has happened on the northern section in past fire seasons.

None of this is something you can fully plan for months in advance — it’s something you check right before you leave and again each morning you’re on the trail, against the PNRC’s own current alerts rather than a guidebook or an older blog post (including, eventually, this one).

Summary: The physical terrain is the constant risk; wildfire and weather closures are the variable one, and both need confirming close to, and during, your hike — not just once while planning.

Where does a planning tool like traversly actually fit in?

Booking refuges, reviewing the season, and reading up on resupply gaps is homework you do once, before you leave — pnr-resa.corsica, PNRC, and guides like this one are built for that. What’s harder to plan for in advance is everything that changes while you’re already walking: whether the water source two hours ahead was still running when someone passed it yesterday, whether a bergerie’s shop is actually open this week, or how far the next bed really is once you’ve adjusted your pace to how the terrain is treating you that day.

That’s the gap traversly is built for — not a route planner in the everyday sense (the GR20 is waymarked in red and white the entire way, and most days you won’t need help finding it), but a map to fall back on for the rare stretch where you do lose the markers — fog, a snow patch across a col, a waymark scraped off by a rockslide — so you can find your way back to the trail instead of guessing. For everything else, day to day, it’s the navigator: what’s actually ahead on the stretch you’re already on, kept current by other hikers who passed a few days before you, not by an annual guidebook update. It’s launching soon, covers water, shelter, camping, and resupply, and — like the mandatory PNRC bookings above — you buy the GR20 guide once rather than paying a subscription for a trail you might walk once in your life. It sits alongside your PNRC bookings, not instead of them: book your beds ahead of time, then use something built for what’s ahead of you once you’re actually walking. See traversly’s full trail list for what else is covered.

Frequently asked questions

How long does the GR20 take to hike?

Most people finish the full Calenzana-to-Conca traverse in 15 to 16 days, hiking one official stage a day. Fit, fast parties sometimes combine stages and finish in 10 to 12; parties carrying more weight or splitting the harder stages in two can take 18 to 20.

Do I have to book refuges before I go?

Yes. Since the PNRC centralized the system, every overnight in the park — a refuge dorm bed, a rented tent, or a pitch in your own tent on a designated bivouac area — must be booked and paid for in advance on pnr-resa.corsica. You cannot show up and book at the refuge desk.

Can I wild camp on the GR20?

No. Wild camping is banned across the entire Parc naturel régional de Corse, not just near the trail. You can only pitch a tent on the designated, paid bivouac areas attached to each refuge, and that pitch still has to be booked in advance like any other overnight.

Which direction is better: Calenzana to Conca, or Conca to Calenzana?

Calenzana to Conca (north to south) is the direction described in most guidebooks and the one refuge capacity is generally planned around. South to north front-loads the easier, more forgiving stages, which some hikers prefer for acclimatizing before the harder, more exposed northern half — but it means finishing on the toughest terrain rather than easing out.

Which half should I hike if I only have a week or two?

Split at Vizzavona. The northern half (Calenzana to Vizzavona) is cliffier and more mountainous, with more exposure. The southern half (Vizzavona to Conca) is gentler, opens into wider pastures, and finishes in the Bavella needles — closer to a US-style national park than the rest of Corsica.

Corsica is known for its beaches — do I really need mountain gear?

Yes. The GR20 spends almost its entire length above 1,500 meters on exposed ridgelines and granite, with weather that can turn quickly. Equip and dress for a high alpine trail — proper boots, a real hardshell layer — not for a Mediterranean holiday, regardless of what the rest of Corsica looks like from the coast.

Is the GR20 a good first long-distance hike?

Not really, on its own. The terrain is a level up from a well-graded alpine trail — loose rock, chains, granite slabs, and stages with real exposure — and it rewards people who already have multi-day backpacking and scrambling experience. If it’s your first time carrying a full pack for two weeks, do a shorter trial trek first.