GR20 Corsica
19 min readThe GR20 traverses the spine of Corsica from north to south (or vice versa) over 182 km (113 mi) with 12,771 m (41,900 ft) of elevation gain. It's widely considered one of the toughest long-distance trails in Europe — steep, rocky, technical, and remote. We hiked it southbound (SOBO) from Calenzana to Conca in 7 days during late October 2024, immediately after finishing the Tour du Mont Blanc.
This guide is written from that off-season perspective. The refuges were open but unstaffed, we carried all our own food, and we hiked in the dark more often than not. If you're planning the GR20 outside the June–September window, you'll find the practical details here.
| Distance | Elevation |
|---|---|
| 182 km (113 mi) | 12,771 m (41,900 ft) ↗️ 12,741 m (41,801 ft) ↘️ |
Planning
Each day section below opens with a Trail Info callout summarizing terrain, water, shelter, and resupply. If you want the quick version, scan those callouts. They're designed to stand alone as a reference.
All GR20 refuges are managed by the Parc Naturel Régional de Corse (PNRC). In peak season, book through their site. In the off-season, they're open but unstaffed — no booking needed.
When to go
Peak season (June–September): Refuges staffed, meals served, tents and huts bookable. Busy in July–August. Warmer but afternoon thunderstorms common at elevation.
Shoulder season (late September–October, May–early June): Refuges open but unstaffed — no food or amenities. Carry all food and a full sleep system. Trails nearly empty. Shorter days mean night hiking on big-distance days. Water sources generally still flowing in October, but smaller streams may be reduced. Carry 2L+ and fill at every opportunity. This is when we went.
Winter (November–April): Snow on high passes. Crampons and ice axes required. Serious mountaineering experience only.
Tip
Late October gives you solitude and no queues at chains or scrambling sections. The trade-off: shorter days, colder conditions, no refuge services, and you carry everything.
Direction and duration
We hiked southbound (SOBO), the standard direction, all signage assumes it. The northern half is more technical; starting there means you hit the hardest terrain while fresh.
Duration: Standard is 16 days. Fast hikers do 10–12. We did 7 (25–31 km/day, significant night hiking). Only realistic if trail-fit and comfortable on technical terrain in the dark.
Distance on the GR20 is deceptive. A 7 km section that takes an hour on smooth trail can take 3–4 hours here. Trust the time estimates on trail signs. They're calibrated for the terrain. Plan 10–12 days for a first attempt.
Resupply and food
One resupply point: Vizzavona at the midpoint. In peak season some refuges sell basics. In the off-season, you're fully self-sufficient.
I cold soaked every meal: no stove, no fuel, less weight. Packed out bread, cured meat, and cheese from Calenzana. In Vizzavona all stores were closed; we got dinner and breakfast at the hotel.
Gear (off-season)
- Sleep system: tent/bivy, pad, bag to -5°C
- Food: cold soak or stove
- Headlamp + spare batteries (you will night hike)
- Sturdy footwear with aggressive rock grip
- Trekking poles (essential for descents)
- Rain gear you trust
- Warm layers: base, fleece/puffy, wind shell, gloves, hat
- Groundsheet for refuge platforms
- Offline maps (well-marked route but useful for alternates)
Fitness
Northern half has sustained scrambling, chains, and exposed ridgelines. You need: multi-day backpacking experience (12–15 kg pack), comfort with rocky scrambling, ability to navigate in poor visibility, and endurance for 8–12 hour days. If new to scrambling, practice elsewhere first.
Off-season overview
| Pros | Cons |
|---|---|
| Empty trail — almost no other hikers | Refuges open but no services (no food, amenities) |
| Plenty of space in refuges to sleep | You must carry all your food |
| No reservation stress | Shorter days = frequent night hiking |
| Cooler temps for hard climbing days | Weather is unpredictable — rain, cold, wind |
| Fireplaces in refuges with wood provided | Bergeries (lower huts) are closed |
Good to know
Refuges are larger buildings with fireplaces, dining areas, and sleeping platforms. Bergeries are smaller shepherd's huts with less space and fewer amenities. Both have tent sites nearby. In the off-season we stayed inside every night — saves setup time and the fireplaces are a lifesaver for drying gear.
Getting to Calenzana
Transport: We flew into Bastia and took a shuttle bus into town, then a long-distance bus toward Calenzana. In the off-season (October–June), the scenic train to Calvi was shut down for maintenance, with a replacement bus running on an unpredictable schedule. Check municipal websites for current timetables before your trip.
Getting to the trailhead: The bus dropped us about 8 km from Calenzana. We hitchhiked the last stretch. A driver picked us up within 15 minutes. We arrived around 8 PM in the rain.
Accommodation in Calenzana: Camping Calenzana is the obvious option, though it appeared closed when we arrived late in the off-season. We ended up sleeping under a covered restaurant patio in town. If you arrive late in the off-season, have a backup plan. There are a few gîtes and B&Bs, but call ahead to confirm availability.
Food: There's a bakery right at the trailhead — U Castellu di Santarellu — where you can grab breakfast and pack out bread for the first day or two. This was our last food stop before hitting the trail.
Day 1: Calenzana to Refuge de Carozzu
| Distance | Elevation |
|---|---|
| 19 km (11.9 mi) | 2,025 m (6,644 ft) ↗️ 999 m (3,276 ft) ↘️ |
Trail Info
Terrain: The first 8 km are well-packed dirt with gradual switchbacks — a gentle start. After Bocca a U Saltu, the terrain changes to steep rocky scrambling with chains bolted into the rock face. The chains aren't technically difficult if you're comfortable scrambling, but can be nerve-wracking for those new to exposed terrain. Beyond the chains, a ridgeline leads to Refuge de l'Ortu di Piobbu (first refuge, ~3 PM arrival). The remaining 7 km to Carozzu are brutal — signs say "7 hours" for this section. Don't underestimate it. We ended up night hiking the last portion.
Water: Streams flowing before Bocca a U Saltu — fill up here. After Refuge de l'Ortu di Piobbu, get water at Ruisseau de la Mandriaccia before the rocky climb begins. From that point to Refuge de Carozzu there's nothing reliable.
Shelter: Refuge de l'Ortu di Piobbu is the first refuge (~8 km in). Open in off-season, no services. Refuge de Carozzu is the end point — open, other hikers were already asleep when we arrived at 10 PM.
Camp: If you get stuck between the two refuges, there's a spot for one tent just above Bocca Piccaia — flat, slightly exposed, but a beautiful location. Carozzu itself has space to tent nearby.
We grabbed coffee and a pastry from U Castellu di Santarellu near the trailhead and packed out some bread. The trail eased us in with gentle switchbacks, then got serious at the chains section. We reached Ortu di Piobbu around 3 PM and debated stopping — the sign warned 7 hours to the next refuge for 7 km. We shrugged it off. That was a mistake.
Tip
Don't underestimate GR20 distance-to-time ratios. "7 km" on this trail is not a quick hour's walk. It's not just the elevation — the rocky, uneven terrain slows you down constantly. Factor in 1.5–2x the time you'd normally expect, especially with a full pack.
The terrain is relentlessly rocky and we finished the last section by headlamp, arriving at Carozzu at 10 PM, completely spent.
Good to know
Off-season refuges have fireplaces with wood provided — use them. Drying gear and warming up by the fire after a cold, wet day makes the difference between miserable and manageable. The communal fires were some of the best moments on our trip.
Day 2: Refuge de Carozzu to Refuge de Tighjettu
| Distance | Elevation |
|---|---|
| 18 km (11.2 mi) | 2,025 m (6,644 ft) ↗️ 999 m (3,276 ft) ↘️ |
Trail Info
Terrain: Steep climb to Bocca di Stagnu, then descent to Refuge de Asco Stagnu. From there, a forest section before the ascent toward Monte Cinto (2,706 m / 8,878 ft — Corsica's highest peak). The Monte Cinto ridgeline is exposed and technical. Rocky, loose descent to Tighjettu in the dark.
Water: Grab water after leaving Carozzu and again before leaving Asco Stagnu. If you must, fill from Ruisseau du Tighjettu — though you may need to scramble down to the river to reach it. After that, there's nothing on the Monte Cinto ascent. You won't see water again until about 3 km into the descent on the other side.
Shelter: Refuge de Asco Stagnu (many hikers stopped here for the night). Refuge de Tighjettu — has a fireplace with wood provided. We arrived late and found two other hikers who'd already started a fire. From this point, we hiked together for much of the remaining trail.
Camp: No flat ground between refuges on this section — plan to stay at Asco Stagnu or push through to Tighjettu.
Resupply: Everything at Asco Stagnu was closed in the off-season, but the huts were open to stay in — you can use the dining area for eating and starting a fire if needed.
We set off at 8 AM. On the climb to Bocca di Stagnu, a trail runner passed us. He was attempting the GR20 FKT (fastest known time), aiming for 40 hours self-supported. We later learned it was Sébastien Raichon, who set the new unsupported FKT for the GR20 that day, finishing in 44 hours. We were on Day 2 covering the same ground he'd done since that morning.
From Asco Stagnu, most hikers we'd started with called it a day. We pushed on toward Monte Cinto. Rain and mist rolled in during the climb, pelting us all the way to the ridgeline.
As we started traversing above Lac du Cinto, the clouds broke and the sun lit up the jagged peaks. The descent to Tighjettu was brutal: rocky, dark, headlamps on again. We arrived late to find a fire going and two new friends.
Tip
The Monte Cinto ridgeline is exposed and navigation can be tricky in fog or rain. If conditions deteriorate, Refuge de Asco Stagnu is a safe bail-out point. Most hikers we started with stopped there for the night rather than pushing into bad weather.
Day 3: Tighjettu to Manganu
| Distance | Elevation |
|---|---|
| 30.9 km (19.2 mi) | 1,385 m (4,543 ft) ↗️ 1,466 m (4,809 ft) ↘️ |
Trail Info
Terrain: Mix of rocky ascents and forested sections. A notable 7 km stretch of soft, runnable trail through forest — a welcome change from the relentless rock. Passes through Castel de Vergio (a village with a restaurant and some amenities, intersects with the bike touring route of Corsica). Climbs at Col de Saint Pierre and Bocca a Reta before descending to Lac de Nino and continuing to Manganu.
Water: Fill up before the climb to Bocca di Foggialle. Shortly after the pass, there's water at the Ciottulu campsite. As you follow the Golo river down, you can scramble to the river to refill. Lac de Nino has water available around it. Refuge de Manganu has a running stream right next to it — strong enough for a cold shower.
Shelter: Two refuges sit close together near the start: Refuge de Tighjettu and Bergerie de Ballone. Opt for Tighjettu — it's nicer. Bergerie de Vaccaghia further along is cramped (we skipped it). Refuge de Manganu is spacious with a fireplace — our companions had a fire going when we arrived at 9 PM.
Camp: The forested sections have flat ground and water streams nearby if you want to camp wild. Each refuge and bergerie has tent sites surrounding it, though in the off-season we slept inside the buildings to save time on setup.
Resupply: Bergerie de Radule was closed when we passed, but had signs advertising fresh-made cheese for sale (in season, definitely worth stopping). Castel de Vergio has a restaurant and a few amenities — I didn't stop but it's an option if you need it. No other resupply until Vizzavona (Day 4).
We took a relaxed start and our two new hiking companions set off ahead. A few km in, I realized I'd left my groundsheet back at Tighjettu. No going back. The forested 7 km section was a welcome change from the rocky terrain and let us cover ground quickly. At Bergerie de Radule, signs advertised fresh cheese, closed in October, but in season it would have been a great stop.
Past Castel de Vergio, the trail flattened into a runnable forest path before the climbs to Col de Saint Pierre and Bocca a Reta. Lac de Nino appeared out of the fog as we descended — dramatic and unexpected. We stopped and considered staying at Bergerie de Vaccaghia but decided to push to Refuge de Manganu. The right call — it was much bigger, had the running stream, and our companions had a fire going with foraged wild mushrooms for dinner. A long day ending well.
Good to know
Corsica's forests are full of edible wild food in autumn — mushrooms in the shaded valleys and arbouse (strawberry tree berries) along the lower trails. One of our companions foraged Lactaire sanguin (Lactarius sanguifluus) for dinner at Manganu — a prized edible mushroom commonly found under Corsican pines. Just know what you're picking, some species look similar to toxic ones.
Day 4: Refuge Manganu to Vizzavona
| Distance | Elevation |
|---|---|
| 26.7 km (16.6 mi) | 2,006 m (6,581 ft) ↗️ 2,440 m (8,004 ft) ↘️ |
Trail Info
Terrain: Technical ridgeline with chains/rappel section at Bocca de la Porte. Rock scrambling at Bocca Soglia. An alternate ridgeline route via Col du Bocca Manganello shaves time. Long descent into Vizzavona through forest. This was the most technically demanding day.
Water: Fill up before leaving Manganu or along the stream on the initial ascent. From Bocca alle Porte to Refuge de Petra Piana there's no water — carry enough for the full ridgeline section. Descending toward Bergerie de Tolla you'll cross a few streams. Water available at Refuge de L'Onda. On the rocky descent to Vizzavona there are streams as well.
Shelter: Refuge Petra Piana (lunch break in the sun). Refuge de L'Onda (we didn't descend to it — continued on the high route). Vizzavona — we hitched to Chambres d'hôtes Casa Alta when everything at the trailhead was closed.
Camp: Some nice flat spots along the rocky descent to Vizzavona, with water nearby.
Resupply: Vizzavona is the GR20 midpoint and your first real resupply opportunity since Calenzana (4 days). In peak season there's a grocery store and some shops. In October, everything was closed — we didn't resupply here. We hitched a ride with day hikers to Chambres d'hôtes Casa Alta in Forêt de Vizzavona. More expensive but well worth it for the hot dinner, breakfast, and a real bed after 4 days on trail.
Bathrooms: Full facilities at the hotel.
We set off determined to reach Vizzavona, the midpoint and first chance to resupply. The ridgeline climb to Bocca de la Porte was tough but exhilarating, with a controlled rappel section using built-in chains. Keeping pace with our more experienced companions pushed my limits. At Petra Piana we stopped for lunch in the sun. One companion suggested the direct ridgeline route via Col du Bocca Manganello. It shaved off time and gave us enough daylight to push through.
We passed Refuge L'Onda at 4 PM without stopping. The long descent into Vizzavona felt endless but we were motivated by the thought of pizza ("Pizzavona" became our mantra). Arrived at 7 PM to find everything at the trailhead closed. Hitched a ride, ran into a trail friend who shared his hotel room, and the staff kindly upgraded us and prepared a hot meal. After 4 days of trail food, a real bed and hot dinner felt like pure luxury.
Day 5: Vizzavona to Refuge di u Prati
| Distance | Elevation |
|---|---|
| 30.8 km (19.1 mi) | 2,131 m (6,990 ft) ↗️ 1,252 m (4,109 ft) ↘️ |
Trail Info
Terrain: Technical scrambling up Punta Scarpiccia — one of the most technical sections on the entire trail. Easy to get off-route, so pay close attention to markings. After descending to Bergerie de Capanelle, the trail mellows into forest sections past Bergerie de Gialgone and Col de Verde with plenty of wild camping opportunities. After Col de Verde the terrain turns rocky again climbing to Refuge di u Prati.
Water: Water at Bergerie des Pozzi, then nothing until you descend to Bergerie de Capanelle. The forest sections between Capanelle and Col de Verde have streams. Fill up at Refuge di u Prati — the rocky ridgeline to Refuge d'Usciolu is dry with no camp spots either.
Shelter: Refuge di u Prati — we met a new group of hikers here. Watched a lightning storm rolling in from the east while eating dinner inside.
Camp: Plenty of wild camping spots through the forest sections between Bergerie de Capanelle and Col de Verde. After Prati, no viable camp spots until Refuge d'Usciolu.
Resupply: None between Vizzavona and the end. We carried all our remaining food from Calenzana — no resupply was possible.
One of our hiking companions had to leave at Vizzavona. His ferry departure was approaching. That left two of us for the remaining 3 days. We navigated onto a harder route up Bocca Palmente by mistake, steeper and more technical than expected with some serious scrambling. Having a partner made all the difference mentally and physically.
After the summit, the terrain mellowed but the sun was setting and we were hiking in the dark again. Out of 7 days on trail, we hiked by headlamp for 5 of them. The combination of long distances and short October daylight made night hiking the norm rather than the exception.
We reached Prati and met a new group of hikers. While eating dinner, we watched a storm rolling in from the east: lightning flashing across the island with distant thunder. A dramatic end to a long day.
Day 6: Refuge di u Prati to Bergerie d'Asinau
| Distance | Elevation |
|---|---|
| 26.9 km (16.7 mi) | 1,506 m (4,942 ft) ↗️ 1,778 m (5,833 ft) ↘️ |
Trail Info
Terrain: Rocky ridgeline from Prati to Refuge d'Usciolu, then descending terrain crisscrossing Ruisseau de Veracolongu. Past Bergerie l'Croci the terrain continues to Bergerie d'Asinau. The bergerie was under reconstruction — only a small temporary shelter was available.
Water: Fill up at Prati — the ridgeline to Usciolu is dry. Descending from Usciolu, you crisscross Ruisseau de Veracolongu where water is plentiful until Bergerie l'Croci. Fill up at l'Croci — no water again until Bergerie d'Asinau. Fill there too, that should last you to Bavella the next day.
Shelter: Refuge d'Usciolu (passed through). Refuge d'Asinau (reached at 5 PM, debated stopping). Bergerie d'Asinau — under reconstruction, small temporary shelter. Not comfortable but dry when rain started.
Camp: No viable spots on the ridgeline between Prati and Usciolu. After Usciolu, some options along the river sections. Bergerie d'Asinau has space for tents.
Bathrooms: Nothing reliable at the refuges on this stretch. Hold out for Bavella the next day — restaurants there have restrooms.
We left Prati at 8 AM and made steady progress through alternating rock and forest. Passed Usciolu without stopping. Reached Refuge d'Asinau at 5 PM and debated calling it, but with daylight left we pushed to Bergerie d'Asinau, arriving at 7 PM.
The bergerie was under reconstruction, just a small temporary shelter. Some hikers built a fire outside and we gathered around for dinner. I made the mistake of drying my soaking shoes too close to the flames and burned the lace loops. Managed to repair them, but a frustrating way to end the penultimate day.
Day 7: Bergerie d'Asinau to Conca
| Distance | Elevation |
|---|---|
| 29.2 km (18.1 mi) | 854 m (2,803 ft) ↗️ 2,170 m (7,117 ft) ↘️ |
Trail Info
Terrain: Mostly descending. Passes through Bavella (small town with restaurants) and past Refuge di i Paliri (scenic, nestled beneath a rugged mountainside with gorgeous views of Punta Tafonata). One small pass at Bocca d'Usciolu, then it's downhill into Conca.
Water: Streams through the section after Bavella. After Bocca di Villaghello it's mostly downhill and you probably won't need much until Conca.
Resupply: Bavella has a few restaurants open — we stopped for a proper meal, the first since Vizzavona. This is the last food option before Conca. Right before the finish sign in Conca, Le Soleil Levant bar is a great spot to grab a celebratory drink.
Camp: Not needed if finishing in one day. But Refuge di i Paliri is a beautiful overnight stop if you want to stretch the final day into two — plenty of tent space and great views.
Bathrooms: Restaurants in Bavella. Bar in Conca.
The rain from overnight tapered off and we left around 8 AM. Final day energy carried us through. By midday we reached Bavella and stopped for a hot lunch at one of the restaurants, the first cooked meal since Vizzavona two days prior.
Past Refuge di i Paliri, we decided to run sections of the trail in 5 km intervals, making the most of the last day. The terrain was mostly descending and we were feeling strong. When the trail met the road into Conca, we sprinted the final stretch to the trailhead sign next to the local pub.
That night we stayed at a B&B in Conca, washed everything, and had a celebratory dinner.
Reflections
The GR20 demands a high level of fitness and comfort with technical mountain terrain. It's steeper, rockier, and more sustained than anything else I've done in Europe. The off-season added another layer: short days meant we hiked in the dark 5 out of 7 nights, and we carried all our food with no option to resupply until the midpoint.
What made it work: having experienced partners, carrying lightweight but warm gear, and staying flexible with daily targets. The trail rewards self-sufficiency, and the off-season solitude made it feel genuinely wild.
Getting home from Conca: Our B&B host gave us a ride from Conca to Porto Vecchio. From there, we hitched two rides to Bastia. We spent a few days relaxing on the beach before catching our flight home.
Tip
If you're hitchhiking, start from Porto Vecchio. It has much more through-traffic heading north than Conca does.
Thanks for reading! If you have any questions about hiking the GR20 in the off-season, get in touch or find me on Instagram: @andrewtpham.
Happy trails!