GR20 - From Calenzana to Conca

The GR 20 (Grande Randonnée 20) is often cited as one of Europe's toughest and most spectacular long-distance footpaths. Traversing the length of the French Mediterranean island of Corsica, it delivers a rugged immersion in high-mountain granite landscapes, chestnut forests, emerald tarns and airy granite ridges.

Total length: ~180kmAccumulated height: 12.000mDuration: 12-16 days

We hiked the route in 15 days in mid-June 2025. The snow was already gone and the weather was perfectly stable, with 33-36°C at sea level. You get a lot of sun on the GR20, but as long as you stay up in the mountains the temperature remains bearable.

I can recommend the guidebook "Trekking the Corsica GR20" from Knife Edge Outdoor Guidebooks. It contains a lot of useful information, such as water sources and which sections are difficult or require particular care.

Take a look at this video to get an impression about this trip:

How did we do GR20 ?

We hiked it self-guided. From what we saw, most people do it on their own and only a few join a guided group. At least for the northern part I would recommend having the track on your phone or watch - the waymarks are not always easy to follow.

We carried our own tent and some food. The pack weight was around 20% of each person's body weight. Be aware that you carry this for 12-16 days, including climbing and scrambling sections. For us the GR20 was considerably harder than what we had experienced in the Alps before, on the Tour du Mont Blanc or on the Munich to Venice trail.

Looking back, I am glad we had no weather problems. We started between 8:30 and 9:30 in the morning and arrived between 5 and 7 in the afternoon. That worked well for us, but it might not work in July or August, when bad weather has to be expected in the afternoon. Many people set off between 4 and 6 in the morning.

We booked all campsites in advance to avoid paying twice. In our case that worked out. Still, I keep wondering what to do when the forecast tells you not to continue. With our own tent we were flexible - the worst case would have been forfeiting a reserved pitch. We were told that a deviation of one day either way is not a problem.

Would I do it again? I would love to, but with far less weight. What I have not worked out is how to actually reduce it - other than booking very early and sleeping in the refuge beds, which brings the risk of bedbugs.

Day 1 - Calenzana to Refuge d'Ortu di u Piobbu

Length: 11kmWalking time: 6h30minAscent: 1.450mDescent: 160m

Apart from the 1.450m of ascent, the first day is fairly easy going. It is mostly about getting used to the heat. The campsite at Ortu di u Piobbu is nice, with cold showers only, and the view from it is already fascinating.

After day 1 I thought the GR20 was not as hard as everything I had read suggested - so I was looking forward to the days ahead.

Day 2 - Refuge d'Ortu di u Piobbu to Refuge de Carozzu

Length: 7,6kmWalking time: 7hAscent: 705mDescent: 985m

This stage already involves a lot of climbing and scrambling, which is a good introduction to what the GR20 is really like.

It changed my mind about the route: I started wondering whether we would be able to finish at all if it continued like this.

Day 3 - Refuge de Carozzu to Refuge d'Asco Stagnu

Length: 4,9kmWalking time: 6hAscent: 840mDescent: 690m

The drop into Asco Stagnu is a descent of roughly 35 degrees. You can see the village very early on, but it takes a long time to actually get down there. Asco Stagnu is a pleasant place with a refuge and a hotel. If your shoes are already falling apart - yes, that can happen this early - this is your chance to buy new ones. It is also a good place to abandon the route, since it can be reached by car.

I would personally recommend having dinner at the hotel. It costs almost the same as the refuge, but is far better.

Day 4 - Refuge d'Asco Stagnu to Refuge de Tighjettu

Length: 8,4kmWalking time: 8hAscent: 1.200mDescent: 955m

This is the queen stage of the GR20, and I personally would not tackle it in bad weather. There is a lot of climbing involved and it takes considerably longer than you expect.

Day 5 - Refuge de Tighjettu to Refuge de Ciottulu di i Mori

Length: 6,6kmWalking time: 4h30minAscent: 690mDescent: 400m

Time to recover. The trail is relatively easy.

Day 6 - Refuge de Ciottulu di i Mori to Refuge de Manganu

Length: 24,5kmWalking time: 8h30minAscent: 700mDescent: 1.090m

The trail is easy, but 24km is a long way with a full pack. We did not quite make it to Manganu and stopped at the Bergeries de l'Inzecca instead, about 1.5 hours short of it. The advantage is a shorter day and really good food at the bergerie; the downside is that the following stage becomes longer and should not be underestimated.

Day 7 - Refuge de Manganu to Refuge de Petra Piana

Length: 8,5kmWalking time: 6hAscent: 855mDescent: 615m

The queen stage was behind us, but this one comes with similar challenges, and the quoted six hours are probably very optimistic.

Day 8 - Refuge de Petra Piana to Refuge de l'Onda

Length: 10kmWalking time: 4h30minAscent: 480mDescent: 885m

Another day to recover a little. Easy going, much of it under trees. Nice campsite with very good food - you can even pay by credit card.

Day 9 - Refuge de l'Onda to Vizzavona

Length: 10,4kmWalking time: 6hAscent: 680mDescent: 1.190m

Arriving in Vizzavona means the northern half is done. The campsite has a well-stocked shop and there are a few restaurants for dinner - most GR20 hikers seem to end up at "Le Refuge".

The photo shows what the trails look like, at least in the northern section: often barely visible, so you have to keep an eye out for the waymarks.

Day 10 - Vizzavona to E Capannelle

Length: 13,9kmWalking time: 5h30minAscent: 990mDescent: 310m

Capannelle can again be reached by car and appears to be a ski area in winter. Dinner and breakfast are available at the Gîte U Fugone, and we enjoyed the dinner very much.

Day 11 - E Capannelle to Refuge de Prati

Length: 17,3kmWalking time: 6h30minAscent: 945mDescent: 725m

It takes time, but the trail is far less demanding than the northern stages. Prati is a nice campsite with plenty of space for tents.

Day 12 - Refuge de Prati to Refuge d'Usciolu

Length: 10,6kmWalking time: 6hAscent: 755mDescent: 830m

Hiking along the crests takes time and involves a fair amount of climbing.

Day 13 - Refuge d'Usciolu to Site d'Asinau

Length: 15,8kmWalking time: 8hAscent: 975mDescent: 1.185m

We hiked directly from Usciolu to Asinau via the variant, rather than going via Matalza. It is a long day and the trail is not really demanding - the only difficulty was that the waymarks had been removed, painted over in a stone colour. If you take this route, it is a good idea to know the line of the trail beforehand. The signs also suggest that the variant has officially been closed by the national park. I understand the motivation, since the route is not particularly challenging; the real challenge at the moment is finding those painted-over waymarks.

Day 14 - Site d'Asinau to Refuge de Paliri

Length: 15kmWalking time: 6hAscent: 610mDescent: 1.090m

Almost everybody recommends taking the alpine variant here. It does come with some challenges, but the views are extraordinary and impossible to capture in photographs. In the southern section this is probably the most beautiful part of the whole route - do not miss it. You can stop for a coffee or a crêpe in Bavella.

Day 15 - Refuge de Paliri to Conca

Length: 13,3kmWalking time: 5hAscent: 405mDescent: 1.230m

The final stage - almost done. The only real difficulty is the sun and the heat, which become more intense the further you descend.

Our Learnings

• Every refuge serves breakfast and dinner. Apart from saving money, there is no need to carry food
• You have to fill up your bottles at the refuges. We were two people carrying three litres each, and we were glad to find additional water sources along the trails. We used the Katadyn "BeFree" filter and had no issues
• Take plenty of sunscreen - you hike roughly 90% of the time in full sun
• Most people use the rental tents at the refuges to avoid carrying their own. That is a matter of preference, but you have to book very early to be sure of getting a rental tent or a bed
• We carried our own tent, and on some campsites it was hard to find a decent pitch
• There is a lot of climbing involved. Pack everything inside your backpack, otherwise anything strapped to the outside will suffer against the rock
• Check your shoes beforehand and make sure they are in good condition - a surprising number of people end up with broken footwear after a few days