GR20 in 7 days south to north.


Posted: Wed, Aug 8, 2018, 7:26

Hi! going to travel along GR20 at 28.09.2018-05.10.2018. As schedule is quite ambitious i would like to take with me only crucial gear and to reduce the backpack weight to a minimum. I already read forum threads but still got some questions:
Water resupply - 1 liter will be enough to carry between water sources, or should i consider more?

Tent and sleeping mat and sleeping - should i take it with me, or there will be place in shelters along the way, what variant is more comfortable? This is quite significant part of my backpack at the moment.

Food supply - as i understand from forum topics there will be some food supply points available, but i would like to understand how many of them, should i take food with me for first half of trail until Vizzavona?


Posted: Wed, Aug 8, 2018, 9:00

Some water sources were already dry mid-July, and it's very likely more will be by the end of this summer, so... better carry enough water to stay on the safe side. Many people recommend 3L per stage. People here who did the whole thing recently will have better insights into the availability of water :)

There are (relatively) few hikers on the GR in late Sept/Oct, and most refuges cease activity on Oct 1st. The dorms will stay open as usual, but off-season you won't be able to book accommodation, rent a tent, buy supplies, or order a meal. It should be safe to pack only a sleeping bag; if some refuge happens to be overcrowded, just bargain some square inches of sleeping mat with your neighbours...

[A limited range of basic, expensive] food supplies are sold in Conca, Vizzavona, the Vergio and Asco hotels, and Calenzana. Off-season, don't rely on refuges and sheepfolds for food resupply.


Geologist in Corsica


Posted: Thu, Aug 9, 2018, 7:21

Thank you for your replies!
I will consider 2l of water as reasonable minimum.
As for shelters:
D7 Calenzana - Refuge d'Asco Stagnu
D6 Refuge d'Asco Stagnu - Castellu di Vergio
D5 Castellu di Vergio - Refuge de Pietra Piana
D4 Refuge de Pietra Piana - Vizzavona
D3 Vizzavona - Ref Prati
D2 Ref Prati - Refuge d'Asinao
D1 Refuge d'Asinao - Conca

I consider these stops, and my questions is will it be possible to stay in Vizzanova and Castellu di Vergio. Guide states that there are hotels available and this is fine for me, but for Castellu di Vergio seems to be fully closed.

As for food i assume it is better to take all necessary food with me.


Posted: Thu, Aug 9, 2018, 7:38

At Vizzavona you could stay at the Gite d'etape L'Alzarella open from May thru October (phone +330495311319), it has a camping ground with tents for rent and a dorm for 14.

Regarding Castel di Verghio: why not sleep at Ciottulu de i Mori instead?



Posted: Thu, Aug 9, 2018, 7:50

Hi, Michele!
Thank you for the Vizzavona contact.
As for Castel di Verghio - now may plan based on doubling the stages and my stages look like:
Day 6 Refuge d'Asco Stagnu - Castellu di Vergio Descent 2100m Ascent 2120m 24km - Distance
Day 5 Castellu di Vergio - Refuge de Pietra Piana Descent 1650m Ascent 1215m 27km - Distance
If I will switch to Ciottulu de i Mori it would mean +15km and -15km to these stage, so it will be difficult plan for day 5.


Posted: Thu, Aug 9, 2018, 9:05

FYI, in the last few years the hotel at Vergio used to wrap things up around Oct. 10-15.

I'm not sure what you mean by "+15 and -15km". You should definitely take into account not only the horizontal distance, not even the descent/ascent values (what about slope?), but also the overall duration of the stage and specific difficulties (screes).
As is, your D6 is quite extreme (it is now the most difficult part of the GR, crossing the Cintu range, a 8+ hours walk in unstable screes; then add to this a steep climb to Foce Ghjalla... we're talking of ~10-12 hours of very intense non-stop walk). On the other hand, your D5 seems extremely easy, you could probably finish it in about 6-7 hours. Why not balance things a bit better? Spending the night in Ciuttulu (if you manage to reach it before nightfall) means you'd just add one hour of very easy walk to the next easy day.


Geologist in Corsica


Posted: Thu, Aug 9, 2018, 12:57

Thank you for your explanation. As I'm going South to north it is difficult sometimes to understand real time on a trail (in my guidebook i have only timing north-south).
I believe i was wrong with my explanation, as i'm going south to north correct sequence look like:

Day 5 Refuge de Pietra Piana-Castellu di Vergio - Descent 1650m Ascent 1215m 27km - Distance
So I will try to reach Ciottulu on day 5.

Day 6 Refuge Castellu di Vergio-d'Asco Stagnu Descent 2100m Ascent 2120m 24km - Distance

Once again, thank you for replies!


Posted: Thu, Aug 9, 2018, 15:24

The direction followed does not change much in terms of difficulty, flat ground is flat ground (e.g. Manganu<->Vergio : a matter of 3 hours in spite of the distance), and it's easier to calculate durations knowing your own average rate of ascent/descent on rocky paths and screes.
Using the original route and stages of the GR as a basis also gives clues as to which durations to expect (it means: taking into account only the genuine Parc refuges, without hotels or other recent thirdparty accommodation).


Geologist in Corsica


Posted: Thu, Aug 9, 2018, 21:19

I'm guessing the stage Calinzana - Ascu Stagnu takes the low level route to Carrozzu, without visiting Piobbu. If it's the high level classic route then it's too much in one day. It still takes me two days to do that on the low level route and three days on the high level route.


Posted: Sat, Aug 11, 2018, 6:08

Paddy Dillon's guidebook has a reverse route summary that includes times for stages and 'in between' parts of a stage.




Posted: Sat, Aug 11, 2018, 11:16

The only stage where there is a really big difference between N-S and S-N is between Calinzana and Piobbu. Going N-S is hard work and for some trekkers it's too much for them and they give up. Going S-N is actually quite easy and almost all downhill. Going S-N you see the fit trekkers already near the top. You see others halfway. Last of all when you reach the bottom you see trekkers who clearly made a big mistake choosing the GR20.


Posted: Sat, Aug 11, 2018, 14:23

I have electronic version of this book and it has only reversed list of facilities along the way in one of the appendices. No info about route options reversed ascent and descent e.t.c.


Posted: Sat, Aug 11, 2018, 15:05

Well - let's have a stab at one of the stages - Stage 4 - ascent 1250m and descent 1230m. If you switch those around you get ascent 1230m and descent 1250m. The 20m difference won't be noticed. Timing one way is 8 hours. Timing the other way is 8 hours. Of course on that stage you can add Monte Cinto at a cost of 1½ hours, but by the time you add rest breaks you can count on it being 11 hours, which is pretty much what I clocked on that stage.


Posted: Sat, Aug 11, 2018, 19:08

Dear fellow hikers!

My name is Varvara. My boyfriend and I complete the whole GR20, North-to-South, on the 5th of August. I have an unusual thing to ask...

When we were at the Refuge de Uscilou, there was a huge storm. My boyfriend lost his hat then. I know this must sound very silly, however it was very important to us, it had a huge sentimental value, as it was given by someone very dear to him.. So if anyone, by some weird unheard-of miracle, finds it in the mountains, and remembers this message, and collects it and please write to me about it - I would be forever, eternally, incredibly grateful, and think of some great reward for it =)

I know the chances are incredibly slim, but no harm in trying, ha?

It was a brown baseball cap hat, with 'tekstyl' written on it.

Thank you so much, and good luck all! xx




Posted: Mon, Aug 13, 2018, 6:30

Thank you all for your replies! MI updated my timing, and allocate more time for difficult stages of the trail.
Still, i've got some outstanding questions about the route:

temperature at night in unmanned refuges, when i stayed in Dolomite winter shelters in October it was freezingly cold cold there, but they got pack of thick wool blankets to cover, what about GR20?

And in general, what is the temperature at night in October (there was a post about it, but it disappeared somewhere and can not be find with the search unfortunately)

Refuge Asinao, is it only bivouac or there are Beds in Refuge as well? (checked site and there is only bivouac option for booking). Is it the only exception?

Is there any official date when Refugio will be un-stuffed? Now 30/09/2018 is the last day available for booking online.

Bedbugs. Found and article with the warning, but is the problem is really serious? If it will be hard to sleep because of the bites probably it is better to consider tent once more time :)


Posted: Mon, Aug 13, 2018, 7:37

In October nights can be very cold. Beware of that. I don't think you'll find any blankets in the refuges. Bring a good sleeping bag. There are no beds in the new refuge Asinau. I think it's the only exception. As a rule the refuges will be unmanned since 1 October. Bedbugs are still a problem. There are talks about them in the forum. It's in French but you may googletranslate it. You may want to use bedbugs repellents, or use a midge net. Don't take your chances.



Posted: Mon, Aug 13, 2018, 11:55

Hello Alexander,
You have a more difficult, than most folks have, journey to make over the GR20....end of season for supplies at the unmanned refuges, doubling up every day, heavier sack carrying supplies and all the rest.
Fewer daylight hours? etc.
Would it be possible to give a report of how you found the journey after you complete?




Posted: Tue, Aug 14, 2018, 7:22

Hello Gaffr!
For sure i will share my report after my trip. Now i'm in prep phase, trying to fit all necessary items in backpack less than 10kg. As for daylight i checked sunrise and sunset for this time of the year and it is fine for me, sunset around 18:00, sunrise around 06:00 including short period of twilight. On easier sections i can walk with headlamp for couple of hours as well.


Posted: Tue, Aug 14, 2018, 10:20

You'd actually have some 14 hours of daylight in early October: nautical twilight ends at ~8pm (20:00), that's when darkness makes you stop walking and pitch your tent :)


Geologist in Corsica


Posted: Thu, Oct 11, 2018, 11:17

Hello Gaffr!
Just returned from GR20. As promissed short report including some info about status of the refuges.


Day 1 Conca - Refuge d'Asinao
I took the high route between Bavella and Refuge d'Asinao
Timing 07:00-17:45
Weather: Sunny and hot. No clouds. No wind.

Day 2 Refuge d'Asinao - Ref Prati
Old route without visiting Matalza Refuge.
Timing 6:45-18:05
Weather: Clouds gathering. Still hot and sunny. No wind.

Day 3 Ref Prati- Vizzavona
Main route.
Timing 6:30-16:05
Weather: Clouds gathering. Strong wind on the passes.

Day 4 Vizzavona - Refuge de Pietra Piana
Valley route between L’Onda and Petra Piana refugees.
Timing 6:50-17:05 (1 hour stop to dry clothes and to eat some hot food in L’Onda refuge)
Weather: Rain starting from 07:30 all day with sporadic stops. Strom wind with snow pellets on the passes. Rain showers and storm wind starting from 18:00

Day 5 Refuge de Pietra Piana- Refuge de Tighjettu
Timing 6:00-21:15
Weather: Hot and sunny. No wind.

Day 6 Refuge Refuge de Tighjettu- Refuge de Carozzu
Timing 06:50-17:05
Weather: Hot and sunny. Some distant clouds. No wind.

Day 7 Refuge de Carozzu - Calenzana
I took valley route between Carozzu and Refuge d’Ortu di u Piobbu
Timing 07:05-15:00
Weather: Clouds, windy, small rain before Calenzana. Rain showers starting from 20:00.


Conca 29/09/2018
Taxi brought me to the starting point of GR20.

Refuge de Paliri 29/09/2018
Friendly guardian with his girlfriend. Were going to close the refuge next day.

Bavella village. 29/09/2018
Cafes, hotels, quite busy. I walked through the Village quite fast.

Refuge d’Asinao 29/09/2018
Dirty (full of sand and soil) and broken tents. About 7 guys were doing “construction” works for new refuge. Good “dry” toilets. Water source and place to cook food. Guardian was cooking as well. Pietra 4.5 euro. Strange music even at midnight :)

Refuge d’Usciolu 30/09/2018
Good feedbacks about guardian and quality of food and food supplies. Was going to work until 10/10/2018

Refuge de Prati 30/09/2018
Already was unstaffed. Toilets and showers closed (lock and chains). Water source nearby. No bedbugs for me, but some were found in the dormitory.

Bocca di Verde 01/10/2018
Was working.
Bergeries de Capannelle 01/10/2018
Was working.

Vizzavona 01/10/2018
Stayed in Gare GR20 refuge. Hot shower! Food offer between 14-16 euros for portion. Pietra beer 4.5. Food supplies available: 2.8 eur for 6 pack of muesli bars. 2.7 eur for canned fish. Warm inside.

Refuge de l’Onda 02/10/2018
Unstaffed. Toilets working. Shower closed. Screw-om canister available in the kitchen.

Refuge de Pietra Piana 02/10/2018
Small but good. Didn’t find toilets or showers opened. Water inside the refuge. No bedbugs. Old potatoes deposit.

Refuge de Manganu 03/10/2018
I passed nearby. Was unstaffed.

Refuge Ciottulu di i Mori 03/10/2018
Still was opened. Food offer 14-22 euro.

Refuge de Tighjettu 03/10/2018
Unstaffed. Warm and spacious inside. Shower and toilets opened. Good refuge. I slept in the canteen.

Refuge d’Asco Stagnu 04/10/2018
Opened. Lot of people around. Shop and restaurant opened.

Refuge de Carrozzu 04/10/2018
Unstaffed. Warm and spacious inside. Toilets opened. 400 Mars bars as safety food deposit (impressive!). Apple tree with apples. Water inside the refuge. Bed bugs are monsters. It was my bedbugs initiation, I suffered from them badly.

Refuge d’Ortu di u Piobbu 05/10/2018
Unstaffed. Toilets opened. Good refuge. Water source 100 meters away from the refuge.

Calenzana 05/10/2018
In five minutes after I walked into the village I caught the taxi.

My kit
Back pack with food and water was around 12 kg. at start with about 2.5 kg of food and 2 kg of water. At the end it was less then 10 kg. I allocated ~400 gr of food per day, including 200 gr for trekking dry-freeze food portion for dinner. No tent and sleeping mat.

Overall impressions
GR20 is a great trail and can be done in 7-8 days without any hard efforts if your bag is lightweight and you have previous trekking experience.
I choose south to north option in order to prepare myself for tough north sections and it was a good strategy.
I enjoyed both south and north sections and can say that both have their own charm.

As for my personal best stages I can name:
Conca to Bavella (probably because it was first part of my journey)
Old route between Asinau and Uscilou refuges.
High altitude route between Refuge de Pietra Piana and Refuge de Manganu and afterwards valley route from Managanu to Castelu du Vergio.
Cinto range.

P.S. Thanks to all active forum members. Your answers helped me to reconsider many things and brought more clarity to my plan.


Posted: Wed, Oct 10, 2018, 21:02

Some impressive doubling up of stages. It would have killed me. It's interesting to see that the refuge staff don't all leave at the same time. I've been on the GR20 when the refuges started opening and were being supplied, but I've never been there when they've been running down at the end of the season. I'm interested to see if they rebuild Asinau fairly soon.


Posted: Wed, Oct 10, 2018, 21:20

GRRR20, when I got there this July I took some pics:

The main building is all wooden with a dining room with tv. Then there is the wooden house of the guardian and further left the toilet block. Still no dormitory.


Posted: Thu, Oct 11, 2018, 6:32

Hi, Michele!
The building on your last photo has been disassembled.


Posted: Thu, Oct 11, 2018, 6:40

Probably disassembled so that it doesn't get burnt down, like the previous refuge!


Posted: Thu, Oct 11, 2018, 6:41

Ouch! That is weird. That wooden building was the dining room and it looked nice. I wonder why they took it down.
Do you have any recent picture of the place? What did they build instead?



Posted: Thu, Oct 11, 2018, 8:04

Thanks for getting back Alexander.

There are many folks who post here hoping to do very short crossings of the GR20 but very few ever get back with a report of their journey.....I guess that perhaps things didn't quite work out with their schedule. It is surely no problem to get back with a report of a trek that took longer than expected.

Tighjettu over Cintu, through Haut Ascu and on to Carozzu….now that is serious pace...well done.

Thanks Michele for the camera? Could it be that the fine wee wooden chalet was taken down to allow for a new replacement stone building?

I am a bit surprised that folks are allowed to use the main refuges in Corsica after the season ends....most alpine refuges have a quite separate 'winter room' which obviously allows for the main building with guardian in charge to be protected from miss-use.




Posted: Thu, Oct 11, 2018, 10:29

I don't have exact photo, but on this one you can see the angle of the basement. There were windows and doors everywhere and wooden planks covered with some insulation material.


Posted: Thu, Oct 11, 2018, 11:11

Hi, Gaffr!
I do agree with you, that information about longer than expected trails is important and quite rare on this forum. As for me i had several back up plans from Form finishing in Haut Asco to Vizzavona.
As for this time of the year I was quite surprised with snow and ice on rocks after heavy rains above 2000m. With the complexity of trail, it creates really dangerous combination, that should be taken into consideration.
The services available in the unstaffed refuges really luxury in the comparison to alpine winter shelters (gas, firewood,electricity!!!, food (sometimes), opened toilets and showers). These questions I was asked really often so I tried to summarize this info for October trekkers, maybe I will create a google sheets form later on.
I took these photo in Prati Refuge during the strormy evening:


Posted: Thu, Oct 11, 2018, 12:39


are you absolutely sure it was the wooden building and not the big white tent? Please take a look at the following picture if compared to yours it looks like what they removed was the big tent. Am I wrong?


Posted: Thu, Oct 11, 2018, 14:22

HI, Michele!
Already not sure, as i found pictures of almost built refuge dated from august 2018, but i was walking on absolutely empty refuge foundation week ago. Lets wait for alternative evidences.