GR20 Trip Report – Sept 2016

GR20 Trip Report – Sept 2016


The GR20 (Grande Randonnée 20) is one of the large network of waymarked walking trails found throughout France, especially in mountain areas. The route follows the spine of the central mountain chain of the island of Corsica. Running roughly from NW to SE, it covers a distance of about 180km and incorporates ascents of some 12,000m (with the same in descent). Due to the nature of the terrain and the facilities available, it is generally regarded as one of the toughest of all the GR routes. The “path” has been characterised as walking along a dry rocky riverbed for 200km. It’s not quite that bad but it is certainly a rugged mountain path that requires constant attention. The route is usually described as being 16 stages which translates into 16 days. However, there are a few short ones where it is possible to double up though doubling up means longer days of 10 – 12 hours.


On our journey from 1st to 9th Sept 2016 we travelled (N to S) as far as Refuge d’Usciolu. See the map above with the Refuge circled. At that location, according to our plan, we were two days from the finish but, due to a knee injury sustained on the stage into Usciolu, we opted to bail out. While that was a bit disappointing, so close to the finish and with the hardest sections done, overall it was a really great trip. The mountain environment is exceptional. We met interesting people and enjoyed their company and stories. The weather was excellent except for one day and we enjoyed each day’s trekking experiences. We used the hired tents at the refuges / bergeries and took the (luxury) hotel options at Asco and Vizzavona. We especially liked the northern section where the dramatic and wild beauty of the terrain is first revealed. We were less keen on the forestry sections the further south we travelled.  The route was challenging, as expected, but perfectly doable for your average fit walker.  Our preparation was good and that paid dividends.

We’d planned to do the GR20 in 2015 partly because we were attracted by its reputation and partly in memory of a friend who had passed away 10 years previously. Unfortunately, a broken hand sustained on a training run put paid to that. A convenient and acceptable alternative at the time was the Tour de Mont Blanc – no scrambling, no need to use the hands, better paths etc. On that occasion we set out from Chamonix with our hopes high and though the weather was poor, we hoped for better to come.  Unfortunately it didn’t and we arrived a few days later in Courmayeur, roughly halfway, in a day long downpour after days of seeing little of the famed beauty. With the forecast remaining poor and a niggling knee problem (precursor to 2016?), we decided to pack it in at that point. A TMB without seeing Mont Blanc just didn’t seem worth it. Comparing the GR20 and the TMB (what we did of each) we can say with certainty that the GR20 is a far more challenging proposition.

Preparation for the GR20

Fast forward to 2016 and the effort we put into preparing for Corsica Mark2. We did our research; we selected our gear and we got into shape.

Research was reading Paddy Dillon’s Cicerone guide and trawling through just about everything we could find on the net.

Gear-wise, we already had most of what we needed and, looking back, we feel we got most things right. Our packs weighed in at less than 10kg for Antoinette and 12kg for me. Plus water which was never more than 2 litres. We started out with some food and that got variously added to or subtracted from as the days went by.

That’s a big bag, Sir. Does it weigh much?

In the 3 months leading up to the walk we each ran almost 1,000km and we did some hill walks and climbing. Some of the running was trail running.  Overall we felt in pretty good shape though we still worried about not spending more time carrying heavy bags and/or doing some multi-day hikes.


We had already travelled to the French Alps a few days before the walk so we began by driving to Toulon and taking a ferry to L’Ile Rousse, 30km east of Calvi. Our plan for the return journey was an overnight sailing from Porto Vecchio (PV) – just south of Conca – back to Toulon, thereby avoiding a long trek back north. The PV/Toulon route appeared to be new for the 2016 season but only had two sailings per week.  The outgoing ferry was on 31st Aug and the return was set for 15th Sept. This already meant at least one double stage to avoid the risk of missing the ferry, though with a sailing time of 6pm, the risk looked small. For anyone contemplating a similar approach, make sure to book a flexi –fare for the return.

In Toulon we were able to park our van in the multi-story Mayol carpark beside the ferry port for a special rate of just over €6 per day, worth it for peace of mind. Plus we were able to sleep quietly in the van the night before sailing at 7.30am. Crossing took 6 hours.

From L’Île-Rousse we got a train to Calvi followed by a taxi to Calenzana, the starting point. We hadn’t booked accommodation in advance in the Gite d’Etape and as it happened Antoinette got the last bed while I got to sleep on the kitchen floor. We’d taken a last minute decision not to bring a tent and while that worked out fine, having a tent would have given a bit more flexibility and would have saved some money. We did bring sleeping bags and mats.

Gite d’Etape Calenzana. Starting out in hope and anticipation.

Due to the alleged presence of bedbugs (subsequently confirmed), we planned to stay mainly in hire tents on the route itself and that posed no issue. We were usually offered a choice of tents. Being in Sept, the number of walkers was already declining fast.

Using public transport on Corsica can prove challenging, as we found out when we took the decision to leave the route. We headed from Usciolu to a village called Cozzano and on arrival there discovered that the Mon to Sat bus service leaves at 7am or so. As we arrived late on Saturday morning, we faced the prospect of looking for accommodation for two nights before (hopefully) making it to Porto Vecchio on time for the Monday ferry. Luckily after 2 hours of trying to hitch a lift from the village (with one vehicle every 10 mins or so) and then walking in the midday heat for over an hour, we were blessed to be picked up by a French couple (Merci Beaucoup) who drove us to a town on the Ajaccio / Porto Vecchio road where we were able to connect with a bus to PV.  That bus journey was an adventure in itself. Glad we had had a couple of beers beforehand, they helped calm the nerves.

Luxury Accommodation. Refuge d’Ortu di u Piobbu . We slept in a tent in the dry stone compound.

Arriving in PV, we found, to our horror, that the only hotels available were costing €300+. It was a long night before we found a place to rest our heads – that too was an adventure.

Next morning, we were able to change our ferry from Thursday 15th to Monday 12th giving us a couple of pleasant days in PV to gaze at the gleaming yachts and ponder what it might mean to be really wealthy.

Early morning on some slabs. Best avoided in the wet!

In retrospect, since we bailed out after 9 days, we couldn’t help asking ourselves if the possibility of finishing in 11 days had tempted us to push too hard. On balance, we don’t think so. We always expected to finish in 13 days or less if the weather was kind, which mostly it was. Also, we had little interest in some of the low level stages towards the end and we would always have extended ourselves to finish with a long day instead of another overnight. We enjoyed each day (with the exception of the bad weather one) and we never felt overly challenged or tired. We were very fit after all our preparations.  The only day we wished away was the double stage from Petra Piana to Vizzavona. That was our one bad day but as we had arrived in Onda (end of the first of the two stages) at 11.20am it was just too early to stop. Unfortunately the wet and windy conditions slowed us down on the seemingly never-ending descent into Vizzavona. 11 hours.

Typical terrain in the northern section. Spot the path….


Doing the GR20 is not the cheapest holiday available! This is roughly what we spent for the two of us, excluding cost of getting to Toulon:

  • Ferry:  €130 (incl recliner seats for the return).
  • Train, bus, taxi: €60
  • Accommodation and food in Gites/ Auberges/Refuges: €400
  • Hotels and meals at Asco, Vizzavona and Porto Vecchio:  €600
    Total: €1,200

This was for 12 days on Corsica so roughly €50 pp/day.  Not cheap but well worth it.

Awesome scenery. Faint path visible heading over to the left foreground.


Our gear was good. Osprey rucksacks, NeoAir Thermarests, down sleeping bags, quality lightweight clothes etc. We used walking poles and they were helpful on the long descents. We also used water bladders which meant we didn’t have to stop to drink. Most importantly, we paid attention to our footwear…we used approach shoes (Five-Ten and Scarpa) matched with Superfeet insoles and good wool socks. We brought plenty of ‘stuff’ for blisters in a pretty comprehensive first aid kit.

Things we brought but wouldn’t if we went again:

  • 2 plates and 2 mugs. We could have done with 2 bowls or even one.
  • A little too much toothpaste, ointments, sunblock, insect repellent – all semi-liquid and adding weight. Better estimation needed next time;
  • Paddy Dillon’s Cicerone guidebook plus the French GR20 topo guide. In the end we tore up the Dillon guide (it was the Cirque de la Solitude version) as we completed each section. Maybe photograph key pages?

Things we should have brought:

  • Ear plugs to block out snoring (not just me!) and other noise, including on the ferry;
  • Spare camera batteries instead of a charger.

Luxuries we did bring:

  • Solar charger,
  • Extra socks,
  • Sleeping mats though they were in fact needed in a couple of places.
  • A blow up pillow (Vango) weighing virtually nothing but really comfy.
  • Tea bags and powdered milk especially to make the mornings a little more humane.
Auberge U Vallone. Stunning location. What a place to spend the night.

The Stages

The table shows the stages we completed and in the times shown. The exact distances and ascents / descents are not our calculations. We’ve taken them from other sources so can’t vouch for their accuracy.

In relation to the guidebook timings, we were generally 15 – 20% faster on most stages but we did find one or two where we needed pretty much the full allocation for whatever reason.

Day From To Distance(km) Time (hr:min) Ascent (m) Descent (m) Comments
1 Calenzana (275m) Ref d’Ortu di u Piobbu (1,520m) 12 05:30 1,360 60
2 Ref d’Ortu di u Piobbu Refuge de Carrozzu (1,270m) 8 06:00 780 917
3 Refuge de Carrozzu Haut Asco (1,420m) 6 04:40 790 640
4 Haut Asco Auberge U Vallone (1,440m) 9 07:00 1,250 1,230
5 Auberge U Vallone Refuge de Manganu (1,601m) 32 11:00 1,260 1,350 Double Stage
6 Refuge de Manganu Refuge de Petra Piana (1,842m) 10 05:50 830 580
7 Refuge de Petra Piana Vizzavona (La Foce, 1,100m) 22 10:30 1,200 1,700 Double Stage
8 Vizzavona Bocca di Verdi (1,289m) 32 10:00 900 800 Double Stage
9 Bocca di Verdi Refuge d’Usciolu (1,740m) 16 07:30 1,290 880
10 Refuge d’Usciolu Cozzano + road walk 15 05:00 50 1,200  Escape
Totals 162 73:00 9,710 9,357


Some Highs and Lows

After so long in planning, we were psyched to begin (to borrow a phrase from our American friends). The first 4 days blessed us with magnificent scenery and walking, made even better by great weather and the sense of embarking on a big adventure.

The guardians at the refuges were friendly and helpful and the people we met were interesting.  We hope the Swiss lady who left her wallet at Ref Manganu got it back. A tribute to the honesty of all who stayed that night…the wallet was still hanging unclaimed on the door to reception the next morning.

Beautiful, but frozen for 6 months of the year.

It was nice to see a few (literally, 3) Irish faces. It was also nice to meet a few “father and son” teams and it was great to see some young people on the trek.  In fact everyone was very friendly even where language barriers made communication more difficult.

Seeing some of the wildlife (people excluded!) added to the walk. The black and yellow Corsican Fire Salamander was spectacular to see in the wild, as were the Mouflon near Asco. On the other hand we were forced uncomfortably close to feral pigs on the final descent into Cozzano.

A tough ascent with a dramatic finale.

The low points included when Antoinette developed a stomach bug and all that goes with it on Day 2 at Carrozzu. Being unable to eat dinner, this looked serious but fortunately all was well again by morning. Phew!

We tried to stay in the Bergerie de Vaccaghja about 40 mins before Manganu. They refused to take us even though we could have slept outside. At that stage we had been walking for 10 hours and really didn’t want to pick up our bags and begin climbing again. It was a bit strange as it didn’t look at all full.

Share the love. It’s not all about rocks. Doesn’t look a day over 300 years old (the tree, that is).

Day seven was misery weather wise. Taking the unplanned and longer low level route due to mist, rain and high winds, we arrived in Onda at 11.20am. There we took the decision to press on, despite the arrival of two walkers who had set out earlier and who were forced by the bad weather to return to Onda having reached 1,900m. We were a bit worried what we might find high up but they told us others had gone and so we figured we had a chance. As luck would have it, the wind eventually died down, though the rain and mist got worse. In the end it was two miserable walkers who arrived at the quaint and historic Hotel D’Oru, at the Col de Vizzavona where we enjoyed a lovely meal in the restaurant and a sound night’s sleep.

Dawn at Refuge d’Usciolu, our last one. Level campsites at a premium.

Our final disappointment was in having to quit. We know we could have completed by turning a planned two days into three or four but we had no real interest in just struggling on. The GR20 is a great trek but to be honest, it’s not that good, especially on the southern low level options.

What’s Next?

With retirement from work now looming on the horizon (actually, shining like a welcoming beacon) we will hopefully have more time, good health and resources to repeat the experience of stepping away for a while from the complexity and stress of our 21st Century lives.  The Sierra High Route? Torres des Paine? Manaslu circuit? Who knows…

Mediterranean dawn in Porto Vecchio on our last day on Corsica.