The French Grande Randonnée No. 20, better known as the GR20, is an 115-mile (186km) long hiking trail in Corsica. It’s also routinely described as the toughest long-distance hiking trail in all of Europe. Why? Well, it may be the fact that underfoot you could be dealing with anything from loose rock to snow to puddles. It could be the extreme heat and cold that comes with that - or the climbing. The trail can demand over 1000m of vertical ascent in just a few miles.
Equally, it could be the fact that you’ve got to walk for hours on end, on tough terrain, day after day for around a fortnight. That's simply what it takes in order to complete the trail. And you won’t be enjoying luxury hotels en route.
You’re going to climb above the height of Ben Nevis on day one alone - with over 1,500m of ascent
So, if the GR20 is so demanding, why walk it at all? As most hikers know, good views might come free in the great outdoors, but the best don’t come without a bit of hard work. As Paddy Dillon writes in his Cicerone guidebook, “the GR20 climbs high into the mountains and stays there for days on end, leading ordinary trekkers deep into the sort of terrain usually visited only by mountaineers.”
Between the northern starting point at Calenzana (near Calvi, Corsica’s capital of culture) to the finish at Conca in the south, there are hidden mountain lakes, sea views, rugged, rocky cliffs and remarkable panoramas.
Over the course of the GR20 you’ll cross the rugged, challenging northern segments and the southern part of the route, which is smoother and (slightly) easier to traverse. Both are beautiful. Below we take a look at the 16 stages of the high-level GR20 route, day by day - your introduction to the toughest trek in Europe. The variant described may be different to others you encounter, as it takes the high-level route at every option, making it even more demanding.
It’s important to note that these route descriptions are only short summaries, designed to inspire but not to serve any navigational purpose. They are not intended to guide you on the route and further mapping and planning (or a local guide!) will be required if you want to safely walk any of the trails featured.
Read more: North vs South: Which Half of Corsica’s GR20 Trail to Hike?
GR20: Map & Basics
- Distance: 115 miles (186.5km)
- Start point: Calenzana
- Finish point: Conca
- Days required: 16
- Total ascent: 12,775m (41,915 ft)
GR20: A Guide to the 16-Stage Route
Stage 1: Calenzana to Refuge d’Ortu di u Piobbu
- Distance: 7.5 miles (12km)
- Walking time: 7 hours
- Ascent: 1,550m (5,085 ft)
There’s no easing into the GR20. You’re only travelling seven and a half miles on this opening hike, but it starts off steep. You’re going to climb above the height of Ben Nevis on day one alone — with over 1,500 m (4,921 ft) of ascent.
It’s a constant climb, through a variety of maquis and pine forests, but you’ll be getting your first taste of the rugged mountain views. After a long ascent through a boulder-strewn slope, you’ll reach the Bocca a u Saltu (‘bocca’ means ‘pass’ in this context). From here, it’s a hike to the Bocca a u Bassiguellu, over some rocky notches and outcrops. Descend over the pass and follow the path downwards into a valley. It rises again, past pines and broken rock, to Refuge d’Ortu di u Piobbu.
There are low-level variants of this stage to be walked, if the weather is bad.
Stage 2: Refuge d’Ortu di u Piobbu to Refuge de Carozzu
- Distance: 5 miles (8km)
- Walking time: 7 hours
- Ascent: 750 (2,460 ft)
You’re only going five miles today. Easy, right? Of course not. This is the GR20. Expect to take around seven hours to navigate the mixture of woodland and open mountain. Today, you’ll climb up to the beautiful viewpoint at Bocca Piccaia (1,950 m/3,116 ft), a gap in the rock where you can see the rugged pinnacles and peaks of Ladroncellu Valley. You'll climb along a rocky ridge to Bocca d’Avartoli, navigating scree slopes and rocky gullies, then drop down to Bocca Carozzu, following a steep path downhill through boulders and a birch woodland to the refuge.
Again, there is a low-level variant to this route, which you can also choose to walk.
Stage 3: Refuge de Carozzu to Ascu Stagnu
- Distance: 3 miles (5km)
- Walking time: 6 hours
- Ascent: 860m (2,820 ft)
The three miles ahead in stage three are not easy — and there’s no low-level alternative. Expect to be on the trail for around the same amount of time as stage two. Leaving the refuge, you’ll climb steeply almost immediately, for miles on end. You’ll cross a scenic suspension bridge, then climb over the sloping Spasimata Slabs (there are cables to aid you). The path traces the contours of a rock valley, passing over a ridge to Lac de la Muvrella, a lake situated at 1,860 m (6,102ft above sea level). It eventually reaches Bocca a i Stagni (2,003 m/6,572 ft). Finally, you’ll descend to the ski centre at Ascu Stagnu.
Stage 4: Ascu Stagnu to Auberge U Vallone
- Distance: 6.3 miles (10km)
- Walking time: 8–9 hours
- Ascent: 1250m (4,100ft)
Until 2015, stage four of the official route took you through the Cirque de la Solitude, a plunging rock chasm that needed to be ascended and descended. This was closed after a fatal accident, and now the route takes you along the ridge of Monte Cinto instead. At 2,706 m (8,878 ft), the mountain is the highest point on the island, though ascending to the actual summit is a detour from the route.
Get an early start today, as you’ll be on the trail for the best part of eight and a half hours (or more if you go up to the mountain summit). Climb a steep rocky slope, aided by chains. The terrain becomes gradually steeper, with loose scree underfoot, as you ascend to Monte Cinto. You’ll be scrambling on either side of the peak, but the view out over the GR20 mountains and the island of Corsica makes it all worthwhile. Descend. When you pass the perilously perched Refuge Tighjettu, you're almost done for the day.
Stage 5: Auberge U Vallone to Hôtel Castel di Vergio
- Distance: 8.8 miles (14km)
- Walking time: 6 hours
- Ascent: 850m (2,790 ft)
A slightly easier hike today, as you start out on gentle forest paths. You will eventually work your way back up to the rocky mountains, though, climbing up past the Bocca di Foggiale at 1,962 m (6,437ft). Follow the path downhill into a valley, with awe-inspiring views of the pinnacles and buttresses of Paglio Orba.
You’ll pass the Bergeries de Tula (a ruined hut and sheepfold), and continue by the side of a river. Cross the river on a footbridge and continue along the valley, through pine woodland, to Hôtel Castel di Vergio.
Stage 6: Hôtel Castel di Vergio to Refuge de Manganu
- Distance: 10.3 miles (16.5km)
- Walking time: 6 hours
- Ascent: 670m (2,200 ft)
Today you’ll begin by following a well-defined path through a forested valley. You’ll get in good walking form, trading forest for rock, then climb a grassy ridge towards Bocca â Reta (1,883 m/6,178 ft) before descending to Lac du Ninu. Follow the path around the lake, up a broad valley and across the Pianu di Camputile, a grassy plain. From here, it’s a short, steep climb to Refuge de Manganu.
Stage 7: Refuge de Manganu to Refuge de Petra Piana
- Distance: 5.5 miles (9km)
- Walking time: 7 hours
- Ascent: 980m (3,215ft)
Follow the path upstream past a waterfall. There’s a steep, rocky ascent to the head of a valley—from the top are views of gorges, waterfalls and the spiky pinnacles of the Capu a i Sorbi and Punta alle Porte peaks. Scramble uphill across slabs to Bocca alle Porte, one of the highest points on the route at 2,225 m (7,300 ft).
Cut across the slopes of Punta alle Porte, traversing steep gullies and more boulders, climbing across a ridge before pushing through dense scrub to the Bocca Renosu (2,150 m/7,055 ft) and up to Bocca Muzzella (2,342m/7,683ft). Descend to the Refuge de Petra Piana.
Stage 8: Refuge de Petra Piana to Refuge de l’Onda
- Distance: 4.5 miles (7km)
- Walking time: 4–5 hours
- Ascent: 390m (1,280 ft)
This is the higher-level variant; for an easier day’s hike, take the lower-level route, which is more commonly walked on the main GR20 path. Just beyond the refuge, follow the route signposted 'Par les crêtes'. It takes you across steep rocky ledges and knife-edge arêtes towards the dual summits of Punta di I Pinzi Corbini (2,021m/6,631ft), before descending to the Refuge de l’Onda.
Stage 9: Refuge de l’Onda to Vizzavona
- Distance: 7.5 miles (12km)
- Walking time: 8 hours
- Ascent: 990m (3,250 ft)
Again, there is a low-level variant for this stage. This is the high route. Follow the signpost for Vizzavona along a ridge, before hiking and scrambling up to the rocky summit of Monte d’Oru (2,389m/7,838ft). Cross bouldery slopes downhill and descend a broad gully called La Scala. The path zigzags downhill until it reaches a dense forest. Follow it down to Vizzavona.
Stage 10: Vizzavona to Bergeries d’E Capanelle
- Distance: 9 miles (14.5km)
- Walking time: 5–6 hours
- Ascent: 1,000m (3,280 ft)
This is where the easier southern section of the GR20 begins. Follow the path south through woodland, climbing uphill to cross the Bocca Palmento (1,645 m / 5,400 ft), where there are some good views of Monte d’Ora behind you.
The path continues to contour around forested slopes, with mountain views through the gaps in the trees. There’s a gentle uphill climb before following the signpost for the Bergeries d’E Capanelle, which has been converted into a mountain refuge.
Stage 11: Bergeries d’E Capanelle to Bocca di Verdi
- Distance: 10 miles (16km)
- Walking time: 8 hours
- Ascent: 815m (2,675 ft)
Follow the path uphill. The main GR20 route heads downhill (to a low-level variant), but for more of a challenge, continue uphill, following a line of cairns up towards the summit of Monte Renosu at 2,352 m (7,716 ft). The summit leads across a rocky ridge and down a steep, stony slope — you’ll need to follow cairns to descend it. The path levels out as you cross the grasslands of I Pozzi, then head into woodland. From here though, it's roughly downhill to Bocca di Verdi, where you’ll find the rustic mountain chalets of Relais San Petru di Verde.
Stage 12: Bocca di Verdi to Refuge d’Usciolu
- Distance: 10.3 miles (16.5km)
- Walking time: 7–8 hours
- Ascent: 1290m (4,230 ft)
Walk uphill, passing the Refuge de Prati and climbing over boulders to the summit of Punta Cappella (2,041m/6,696ft). You’ll descend across jagged boulders to reach Bocca di Laparo, before passing through a beech wood. Then it's a climb to Monte Formicula (1,950m/6,400ft) and a slight descent to the Refuge d’Usciolu.
Stage 13: Refuge d’Usciolu to Refuge de Matalza
- Distance: 7 miles (11km)
- Walking time: 7–8 hours
- Ascent: 340m (1,115 ft)
An opening scramble takes you along a ridgeline, squeezing through gullies. At the Bocca di l’Agnonu, follow the waymarkers downhill, passing through woodland and crossing the Ruisseau di Partoso river.
As you climb uphill, you’ll pass a pretty chapel, the Chapelle San Petru. Continue hiking up a short, bouldery slope to the Refuge de Matalza.
Stage 14: Refuge de Matalza to Refuge d’Asinau
- Distance: 6.5 miles (10.5km)
- Walking time: 5 hours
- Ascent: 665m (2,180 ft)
Follow the red and white GR20 paint splashes to the Bergerie d'l Croci, up at 1,540m (5,052ft). You'll walk on, continually ascending to Bocca Chiralba (1,743m/5,718ft). Here, things get steeply uphill to Bocca Stazzunnara (2,025m/6,643ft), after which you'll descend sharply to the refuge.
There is also a low-level variant to this stage.
Stage 15: Refuge d’Asinau to Bavedda
- Distance: 4.8 miles (7.5km)
- Walking time: 4–5 hours
- Ascent: 550m (1,805 ft)
Follow the route down through pines and boulders to the Ruisseau d’Asinau river. After an hour or so, there’s a fork in the path. The Alpine variant leads uphill into the mountains. You’ll pass along a stony ridge, dwarfed by intimidating rock towers. You’ll trek between, rather than over, these towers, although you will climb up a large sloping rock slab, with a chain for protection.
Follow a set of ‘rock steps’ towards Punta di l’Acellu (also known as Tour 1). You’ll then cut downhill across a rocky slope and rejoin the main GR20 route, which takes you along grassy, pine-studded slopes towards the village of Bavedda.
There is a low-level variant here, the classic route, as another option for the day.
Stage 16: Bavedda to Conca
- Distance: 12 miles (19km)
- Walking time: 7 hours
- Ascent: 700m (2,295 ft)
The final stage covers a relatively long distance and descends for 1,670 m (5,480 ft) over the course of the day. Follow a rough path across a riverbed, past pines and heather, climbing uphill towards a gap called Foce Finosa (1,206 m / 3,957 ft).
Descend along an old mule track to the Refuge d’i Paliri, before descending through pine forest and scrub. Large stone pinnacles jut upwards through the trees. The path leads downhill, and then crosses the Ruisseau de Punta Pinzuta downstream and head on towards Conca, the end point of the hike.
GR20: Frequently Asked Questions
How difficult is the GR20 hike in Corsica?
The GR20 is one of Europe’s toughest long-distance hikes, with steep climbs, rocky trails, and exposed ridges. Each day involves 6–10 hours of hiking and major elevation gain. While some lower-level variants exist, even these demand strong fitness, hiking experience, and confidence on technical terrain.
How many days does it take to complete the GR20 trail?
Most hikers complete the GR20 in 12 to 16 days, depending on pace, weather, and fitness. The full route is about 180 km (112 miles) and is typically split into 16 stages, each with challenging terrain and steep elevation changes.
What kind of accommodation is available on the GR20?
Accommodation on the GR20 includes basic mountain huts known as refuges or gîtes. These offer bunks, meals, and toilets. Wild camping is not allowed, but tent pitches are usually available near refuges. Booking ahead is essential during the busy summer season.
Read our GR20 Accommodation Guide.
When is the best time to hike the GR20 trail?
The best time to hike the GR20 is from late June to early September, when snow has melted and the mountain refuges are open and staffed. This is also the most stable weather window, though it’s the busiest. Outside this period, snow may block the trail and make navigation dangerous.
Read our guide on When to Hike the GR20.
Should I hike the northern or southern section of the GR20?
Choose the northern section for steeper ascents, technical paths, and rugged alpine scenery — ideal for experienced trekkers. Opt for the southern section if you prefer smoother trails and more accessible terrain, while still enjoying Corsica’s dramatic mountain landscapes.
Read our GR20 North vs South Guide.
What’s the best guidebook for the GR20 trail?
We recommend ‘GR20 – Corsica: The High-Level Route’ by Paddy Dillon, published by Cicerone. It’s detailed, reliable, and includes route maps and practical advice. The Komoot map linked above is also useful for a digital, stage-by-stage overview.
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