Top tips and recommendations for hiking the GR20
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GR20 Statistics – Overall
Total Distance: 112 miles (180 kilometers)
Total Elevation Gain: 41,900 ft (12,775 m)
Total Elevation Loss: 41,800 ft (12,735 m)
Duration: 16 days
Physical Difficulty Level: High, uphill and downhill training highly recommended
Mental Difficulty Level: High, comfort with heights and ledge exposure required
Gear Necessity: Light or ultralight gear highly recommended (see list below); food available along trail, recommended purchasing as you go
Recommended Guides: Cicerone’s Trekking the GR20 Corsica: The High Level Route by Paddy Dillion is an essential guide OR TopoGuides' A Travers la Montagne Corse (in French); The Corsica For Hikers forum is the best online resource for all things GR20
GR20 North Section – Calenzana to Vizzavona
Total Distance: 62 miles (100 kilometers)
Total Elevation Gain: 26,500 ft (8,080 m)
Total Elevation Loss: 24,300 ft (7,400 m)
Duration: 9 days
GR20 South Section – Vizzavona to Conca
Total Distance: 50 miles (80 kilometers)
Total Elevation Gain: 15,400 ft (4,695 m)
Total Elevation Loss: 17,500 ft (5,335 m)
Duration: 7 days
*UPDATE AS OF 5/2019: The Refuge d'Ortu di u Piobbu (the first hut on the North-South hike), unfortunately, succumbed to flames in May 2019. For the most updated information on this refuge, contact either the Tourist Information Centre in Calvi, the Corsica For Hikers forum, or the Facebook GR20 forum. We will update here on our website when we find more information about reconstruction/opening times, camping permits, food availability, etc.
The GR20 trek on the island of Corsica just off the southern coast of France has been dubbed the “hardest trek in Europe” by hiking and trekking guides all over the world. This designation is apt, as the consistent significant elevation gain and loss, coupled with the need to use your hands during dozens of instances throughout the route, make for a challenging trek overall.
Don’t let that scare you off from hiking the GR20, however. As long as you are in good hiking shape and have your wits about you with heights and ledge exposure, it’s likely you’ll be just fine. The biggest danger on the trail overall is bad weather in the high mountains, so be sure to stay put if the weather is foul from the get-go as dry rock is near-essential for some sections in the northern route. Always listen to your gut and don't attempt to continue with a hike that is beyond your comfort level.
Despite its difficulty level, hikers come from all over the world to conquer Corsica’s stunning and unique mountains.
As prepared as I felt I was at the beginning of the GR20 north trek, I didn’t fully comprehend what lay ahead in the coming days on the trail. This blog post will cover recommendations and tips, gear considerations, and more.
The GR20: Overview
The GR20 is classified as a long distance trek, spanning nearly the entire north-south distance of the Corsican island, a total of 112 miles (180 kilometers), with a serious mountain-to-valley elevation variation of about 32,000 feet (10,000 meters) over a 16 day hiking period.
The trail itself is well-marked with red-and-white blazes throughout the entirety of the trail. Be sure to keep to these marked areas as they will provide the easiest and safest direction of travel.
The most common direction of travel is from north to south, as most hikers prefer to get the harder days out of the way first.
Thus, the trail is often broken up into two sections: the north and the south. The north is the most difficult section, as the most technical and grueling days climbing up and down rugged and rocky mountains are largely covered during the first four days heading south.
The northern starting point is the town of Calenzana and the southern terminus is the town of Conca. Some hikers who complete the whole trail jump into the clear blue ocean at Calvi, just north of Calenzana, and finish by jumping in the ever bluer waters of Porto Vecchio, just south of Conca.
The aforementioned guides and online resource have nearly everything you need to know about each stage of the hike, day by day. The Cicerone guide has incredibly detailed information (nearly turn-by-turn) and includes nearly everything you’ll ever need to know about the hike, and the Corsica for Hikers forum is a great place to ask those who have hiked the GR20 or plan to hike the GR20 about their experiences.
Doesn't this look enticing? The ocean view from Pietranera, Corsica. Photo by Christa Rolls
When to go/Best Season to Hike the GR20
Early June to Mid-to-Late October is the recommended time to tackle the GR20. Most refuges and re-stock locations will stay open through September.
You will want to wait until the refuges are open and when the snow has largely melted away from the main parts of the trail. This is, of course, unless you have more mountaineering experience and plan to hike the trail with the appropriate gear and experience.
Check the trail conditions with the refuges, the Corsica for Hikers website, or GR20 Facebook page – you may need to bring crampons if you go earlier in the summer season.
I went in September and the weather was perfect. All the refuges and various re-stock locations were open and everything wasn’t horrendously busy, though plenty of people were on the trails and at the refuges. There also wasn’t any snow on the trail, and it wasn’t as busy as the trails usually would be in July and August (vacation months for most of Europe). We recommend that you avoid July and August, if possible, to avoid the crowds.
You’ll need to check further into transportation and whether fully places close once you hit October, as this is officially outside of the high season. There also wasn’t any snow on the trail in September, but it wasn’t as busy as the trails usually would be in July and August (vacation months for most of Europe).
A field of tents set up by GR 20 hikers at Refuge D'Ortu Di U Piobbu. Just look at that view! Photo by Christa Rolls
Cost of Hiking the GR20 North
For the GR20 north portion of my visit to Corsica, I spent about €200 on transport and trail necessities. This accounted for:
• Bus transportation from the Bastia airport to the downtown Bastia train station (€9)
• Train from downtown Bastia to Calvi (train station takes credit cards; €16)
• Bus transportation from Calvi to the Gite d'Etape Communal in Calenzana (bus info center takes credit cards; €9)
• Tent space each night at refuges (using my personal tent; €7-9)
• Snacks for the evening (read: end of day beer; prices vary, usually €2-3)
• Periodic lunches for the next day (Barquette or Tabbouleh; around €7)
• Treating myself to dinner two nights (€20 at the refuges and hotels; hotels such as that as Ascu Stagnu will take credit card)
With the purchase of the tent space or refuge bed, use of the showers (which were always cold by the time I arrived) and communal gas stove is free of charge.
Prices for tent spaces and food at the southern refuges are comparable. The cost to rent a tent is typically around €10 and to rent a bed is around €14.
Barquette or Tabbouleh purchased from Refuge D'Ortu Di U Piobbu. Photo by Christa Rolls
Getting to the GR20 trailhead
No matter your direction of travel or hiking, give yourself one full day to travel from one destination to the next in Corsica. Although you will get to where you need to go, sometimes it just takes time and a solid handle on the train or bus schedules. Check out Corsicabus.org for bus and train timetables, and don't hesitate to contact the Tourist Information Centers for more information.
If you are traveling the traditional North to South route, the best option would be to fly or ferry into Calvi directly and begin your journey to Calenzana from there. You can either hail a taxi directly to Calenzana, or explore around Calvi and take the Beaux Voyages once-a-day bus to Calenzana. Note that Beaux Voyages has limited operations times outside of July and August and may only run on weekdays.
Most flights go out of Bastia, but keep in mind that you’ll spend most of the day just trying to get to Calenzana. A handful of times throughout the day, a bus will be parked just outside the baggage claim doors taking people up to downtown Bastia and the train station. Tickets for the train to Calvi can be bought directly at the train station. Consider getting a flight that arrives earlier in the morning to give you time to get to the train station to catch the train, then travel the three hour journey to Calvi.
It might cross your mind, also, to walk to the trailhead at Calenzana from Calvi, but note that it will take an hour or two and you’ll be on a narrow road with no sidewalks – exercise extreme caution when walking these roads and don’t assume you have the right of way.
Trains go between Calvi and Bastia, and Bastia down through Vizzavona and to Ajaccio, the birthplace of Napoleon Bonaparte.
The train does not go to the southern terminus of Conca, or Porto Vecchio, the nearest large city, if you are considering a south to north route. Buses, however, will run from to Porto Vecchio from Bastia and Ajaccio, so you’ll need to consider your route and how to get to the trailhead ahead of time. Rapides Bleus Corsicatours runs from Porto Vecchio to Sainte Lucie de Porto Vecchio, the connecting town to Conca. Contact the Gite de la Tonnelle ahead of time to arrange for a shuttle transfer to Conca from Sainte Lucie.
Keep in mind that bus and train timelines will change outside of the high season – this is typically mid-to-late September.
Accommodation on the GR20
You have a handful of different options for accommodation along the trail.
The first option is to get/reserve a bed at the refuges in one of their communal rooms, or to rent/reserve a tent hired by the refuges. Each refuge has their own set up, but keep in mind that refuge tents are often very limited. If you are planning to trek the GR 20 during the high season, especially July and August, see about contacting the refuges ahead of time to reserve yourself a bed or tent space.*
The next option is to bring your own tent and pay for a space to sleep on the refuge grounds. I didn't have any issues getting a space for my tent, but keep in mind that refuges tend to get busier as you move south.
At some locations there are hotels where you can get an actual room, if you want a hot shower and good bed.
Wild camping is technically illegal along the GR20. In some places, you’ll see spots that have been designated specifically for camping out, but these are few and far between.
*Note: As of the 2018 season, the GR20 forums state there being issues with bed bugs in some of the tents and bed spaces. I didn’t hear of anyone having issues on the northern route in September 2018.
The Auberge U Vallone sits among pines along the rocky slopes of the Ravin de Stranciacone. Photo by Christa Rolls
Food on the GR20
I packed all my own food for the entire northern section trip, but I did also end up getting lunch snacks at most of the refuges to carry for the following day. This, coupled with my Jetboil system, was heavier than I would have liked.
I would recommend having some snacks in your pack for the day, and purchasing most meals at the refuges. This will save you a ton on pack weight, as long as you can manage the refuge meals financially. Otherwise, skip bringing your stove system, as the refuges will offer a gas stove and utensils for cooking.
All refuges will offer some variation of breakfast and dinner, and some a selection of snacks and lunch barquettes. Fewer still will have miniature stores with fresh cheeses or freeze dried meals for purchase. Note that some refuge meals are definitely better than others, both in my experience and based on what my fellow hikers told me. The dinner at Refuge Tighiettu was fabulous (local charcuterie, delicious pasta with sundried tomatoes and olives, and an apple puree for dessert). Friends on the trail raved about the omelets and dinner at Auberge U Vallone.
Breakfast at most refuges will cost you about €9 (usually bread and cheeses) and €20 for dinners (soup or charcouterie, pasta of some kind, and a dessert). The prices are pretty high, but carrying all of the food can be grueling, too. It’s up to you how you want your hiking experience to be.
The food I packed and carried was:
-Breakfast: apple cinnamon oatmeal and Starbucks VIA coffee
-Snacks/lunch: beef jerky, chocolate, nut, and fruit protein bars, LARA coconut bliss bars, fruit leather, cashews, and tabbouleh purchased from the refuges (sometimes it was hard boiled eggs or crackers and cheese)
-Dinner: Couscous and salmon packets, freeze-dried chicken gumbo, freeze-dried veggie burrito, and freeze-dried honey lime chicken and rice for 8 nights total (doubled up on each)
Water on the GR20
For the majority of the northern section you won’t have to worry about filtering water (at least that was the case when I went in 09/2018), and refuge managers will always tell you which water spout is potable or not.
Most people I met on the trail didn’t filter from the tap and experienced no issues.
The southern half of the trail, however, has a different bacteria in the water and it is recommended to only use potable water stations or bring a water filter with you.
I drink a ton of water (about 3L+ in a day during a long hike) so I use the Katydyn 6L Gravity Camp water filtration system that I also kept at camp with me. If you drink like a camel, grab the Sawyer Mini water filtration system – it’s super compact and lightweight, and would be perfect if you didn’t feel you had to filter more than a couple liters.
Nearing the Ford along Le Golo Fleuve - just look at those pools of glorious water! Photo by Christa Rolls
Weather on the GR20
Weather in the mountains can be incredibly unpredictable. On my first night in Calenzana, the weather forecast anticipated only sun for two weeks, and yet a raging thunderstorm came from over the mountains and poured down on us. Thankfully that was the only time during my trip!
Be sure to layer up as well, since the elevation gain and loss will take you to colder and windier places, then back to warmer and less windy locales. Even in summertime the evenings can be quite cool in the mountains.
Always check the weather forecast with the refuge the night before and morning of heading out – don’t go up to the higher mountain passes if the weather looks foul!
Thunderstorm over Calenzana, despite the sunny weather forecast. Photo by Christa Rolls
Miscellaneous tips for hiking the GR20
>> Always leave your itinerary with someone you trust off the trail: The difficulty level of the GR20 should not be taken for granted or lightly - anything can happen in a mountainous and remote region such as the Corsican mountains. Leaving your itinerary and travel plan, and setting up call times to check in with someone, ensures you can be found somewhat quickly if something bad were to happen to you on the trail.
>> Be mindful and careful: Injuries occur every year on the GR 20, usually because people simply get tired or don't watch where they are putting their feet. DON'T get complacent on the trail! Always be mindful of where you place your feet, and only wait until you're ready to continue when you reach a spot that prohibits you from turning around.
>> Learn some French: It will benefit you to learn a bit of French before you head out on your trip. Not all of the refuge managers will be able to speak English or languages other than French (which is technically different than Corsican but is close enough where French is well understood). In addition, many of the people you’ll be hiking and dining with at night will be French speakers. At the very least, learn to say the basic phrases, such as: hello (bonjour or bonsoir), please (s'il vous plait), and thank you (merci).
>> Get good hiking poles, use them when you need to, and know when to put them away. By the latter I mean, when you need to use two hands, don’t fumble around with trying to cling for dear life to your poles simultaneously.
o Nearly all of day 3 I didn’t take my poles out because I felt they would hinder me too much on the ascent and the descent.
o On day 4, I only took my poles out once I got to the long scree field about halfway up the ascent. Otherwise I needed my hands free for most of the first part of the ascent. The descent on the other hand is quite nice and there are only a handful of times that you have to climb down small rock walls.
o Other than these two days, I was able to navigate the rocks with my poles collapsed in one hand.
>> Get good hiking shoes: Make sure your shoes are durable enough to handle essentially rock climbing on rough rock and that the tread isn’t falling apart. This goes along with making sure you have broken your shoes in and have good socks that don’t cause blisters – we recommend SmartWool and Darn Tough, or using a liner sock to prevent rubbing.
>> “Trust your shoes and your feet”. This was the best advice I received on the trail. That seems simple enough, but when you’re literally crawling up scree or climbing up rocks, sureness in your footsteps is what helps to keep you going.
>> Explore other parts of Corsica: Take time before or after the trail to explore other parts of the island and experience Corsican culture.
o I spent a good amount of time in Bastia after my trek and I had a lot of fun. There are options to explore the historic city and eat amazing food, kayak, go boating, take a bus to Erbalunga or Saint Florent and simply explore, scuba dive, horseback ride through the hills of Cap Corse, and more.
>> Lighten your load: If you can swing it financially, only carry enough food in your pack for snacks and some kind of lunch; otherwise, forego carrying all of your food and a stove with you.
o If you must carry a stove, we recommend a small gas stove, or getting a coleman canister to pair with *this tiny setup* and a titanium cup.
o Refuges will have a kitchen with gas available for your use as long as you have paid for a tent space or bed in the refuge.
>> Scope out gas canister options: There are many places where you can purchase gas canisters, the most common type being the pierceable canister. You can purchase adapters on amazon to have these fit to the screw-on canisters, such as those used with Jetboils. However, it’s possible to buy the latter at various locations. The SPAR grocery store at Calenzana will typically have them in stock throughout the season, and various SPAR groceries around the island, especially near the GR20 or in Bastia, will carry them. I found mine at a hardware store a few blocks from the train station in Bastia. Check out The Next Challenge's guide to gas canisters for more information on different types, adapters and more.
>> Take time for a rest day, if you need it. There's absolutely nothing wrong with giving your body a break. This is a tough trek, so listen to what your body needs and modify your hiking days accordingly.
>> Watch for the rock cairns: I would not usually promote rock cairn markers, however, cairns along the GR 20 were always appropriately placed (from what I could tell) and assisted me on many occasions when I couldn't see the GR 20 blaze or when the blaze had been wiped away over time.
The small rock ledge just under the red-and-white GR 20 blaze marks the "hiking" route up rock walls and granite slabs to Ascu Stagnu. Photo by Christa Rolls
Gear recommendations for the GR20
My pack weighed a solid 12 kg without water, which was definitely more than I wanted given my total body weight - your pack should only be about 20% of your body weight. The full list of the gear I brought is as follows –
• Deuter Lite 60+10 SL Hiking Pack
• Small, lightweight, collapsible day pack
• Eastern Mountain Sports 20 degree sleeping bag
• Sea to Summit backpacking pillow
• Thermarest sleeping pad
• Marmot Pulsar 2P tent
• Emergency blanket for tent footprint
• Black Diamond hiking poles
• Petzel Headlamp
• Jetboil stove
• Coleman gas canister
Food and Water:
• Camelback 3 L bladder
• Katadyn 6L water filtration system
• Breakfast, lunch/snacks, and dinner for 9 days on the trail
Clothing and Footwear:
• Vasque hiking boots
• Three pair hiking socks (SmartWool and Darn Tough)
• Reef flip flops
• Three pair Patagonia hiking underwear (originally purchased on discount at REI)
• Two hiking bras (originally purchased on discount at REI)
• One Prana dress
• One pair Prana convertible pants
• Two moisture-wicking long sleeved shirts
• Two moisture-wicking short sleeved shirts
• Patagonia fleece (given to me by a mountain hut manager after someone left it for a month)
• Smartwool long john pants (originally purchased on discount at REI)
• REI puffy jacket
• North Face rain jacket
• Buff neck warmer
Emergency and First Aid:
• First Aid kit: alcohol wipes, antibacterial ointment, antidiarrheal, antihistamines, ibuprofen, antacid, epipen, gauze, medical tape, small round of duct tape, safety pin
• Hiking whistle (check the chest buckle on your hiking pack - some have a whistle built in)
• Waterproof matches
Health and Hygiene:
• Toiletries: wet wipes, face wipes, toilet paper, hand sanitizer, nail clippers, contacts and glasses, sunscreen, mini toothbrush, toothpaste, concealer wand (for after trip), sunscreen lip balm, collapsible brush, shampoo soap bar
• Lightweight camping towel
• Sunglasses and baseball hat
• Corsica guide to hiking the GR20 - comprehensive in detailing alternative routes, accommodation and food options along the trek, and history of the region
Tools and Repair items:
• Repair kit for tent/mattress
• Eiger Dreams by Jon Krakauer
• Eye mask and ear plugs
• Phone charger and battery pack
• Dry bag
• Stuff sacks for organizing gear (e.g., one sack for kitchen, one for food, one for clothes, etc.)
• Credit cards and ID/passport
Keep in mind that I was carrying everything on my own – if I was sharing the load with someone else then I wouldn’t have had to carry as much. After this hike, if I could go back and do it again, I would change/add/remove the following:
• Hyperlite or similar lightweight pack, or smaller Deuter pack size (45-55 L)
• Thermarest foam pad - Lighter weight, though bulkier
• Ultra lightweight 1 P tent
• Ultralight gas canister hookup instead of the full Jetboil setup. However, none of these are necessary, as each refuge offered gas and utensils for free with purchase of tent site.
Food and Water:
• Sawyer mini water filtration - There was potable water at every refuge I visited in the north, so I really didn’t NEED the 6L filtration system, but it was convenient to fill up and take back to my tent without having to walk back and forth.
• Purchase most breakfasts and dinners instead of carrying all of it with me.
Emergency and First Aid:
• In my first aid kit, I only used the ibuprofen twice and the alcohol wipe and antibacterial ointment once (not even from the trail, rather the steps of the first refuge… fail). I’d still recommend bringing a good suite of these things for your first aid kit – you never know when you’ll need it!
• I probably didn’t need Eiger Dreams, but it was a nice read in the sun with a beer after a long day. Mostly though I ended up hanging out and talking with my fellow hiking mates.
• Solar battery charger pack instead of one that needed to be plugged in to recharge
• I could have just done with a high quality, double zip ziploc bag instead of a dry bag, but it did come in handy when I went kayaking after my trip!
Standing at the Pointe de Eboulis, just below the Monte Cinto. Photo by Christa Rolls
Getting around Corsica after the GR20
There are buses and trains to get you around most of the island, but if you want total freedom to visit places not regularly visited by bus or train, you’ll have to rent a scooter or car.
In the summertime and early fall the buses and trains will run quite regularly; outside of this season some routes will stop altogether. Check the Corsicabus.org website for timetables and other information. Otherwise contact one of the main tourist information offices for information about routes and timetables.
Bastia Tourist Information Office
Place Saint-Nicolas, 20200 Bastia, France
+33 4 95 54 20 40
Calvi Tourist Information Office
Chemin de la Plage, Port de Plaisance, 20260 Calvi, France
+33 4 95 65 16 67
Ajaccio Tourist Information Office
3 Boulevard du Roi Jérôme, 20181 Ajaccio, France
+33 4 95 51 53 03
Depending on which city you end up flying out of, you'll have a host of options for different sites to see and activities to do before you head out. Don't miss hanging on one of the island's beautiful beaches for a day to rest your muscles after the strenuous hike. Those found around Cap Corse and the Porto Vecchio region are especially lovely. If you aren't one for laying about on the sand, there are opportunities for snorkeling, scuba diving, boating and sailing, kayaking and stand-up paddle boarding, and so much more at beaches in Corsica.
Most of all, have fun and be safe!
Christa and Nathan