Thirteen days. 180km. 12,000m of ascent. On an island with 120 peaks over 2000m. And I have just a couple of thousand words to tell you about my experience of trekking the GR20. It’s going to be tough.
But then, very little about Corsica’s GR20 is easy. So here’s the deal: you ask the questions (or at least the ones I think you’ll ask) and I’ll provide the answers, gleaned from having spent nearly a fortnight hiking one of Europe’s toughest long-distance trails.
Firstly, what is the GR20?
The GR paths are a European network of long-distance walking trails; GR is an initialism of the French grande randonnée, which literally translates as ‘great hike’. The GR20 threads its way across the Mediterranean island of Corsica and of all the GRs that spider throughout Europe, this Corsican outlier is widely regarded as the toughest.
What makes the GR20 so hard?
Let’s revisit those stats again. A single chain of mountains, including 120 peaks over 2000m high, makes up two-thirds of the island of Corsica, and the GR20 snakes its way from one end to the other. In doing so it stretches roughly 180km and bucks and rears through around 12,000m of ascent - lots of it steep and technical involving some scrambling both up and down. Plus, walking day after day for almost 2 weeks, often with limited sleep and early starts, is draining.
How long does it take to walk the GR20?
Most guidebooks break the trek into 16 stages, but it’s common for itineraries to cover multiple stages in one day for the convenience of completing the GR20 in a fortnight (handy for annual leave and flight schedules), cramming it into 13 days of actual on-the-trail trekking.
How far will I walk each day?
Over 13 days the average daily distance is around 14km. But only on one of those days did we cover less than 10km – most were significantly more, and a couple were well over 20km (the longest was 28km). Plus, with roughly 12,000m of total ascent during the trek (many days are up and down, and up and down, then up and down… you get the picture) that's nearly 1000m of ascent per day. Again, some days are more and some are less, but if you imagine walking up and down a Scottish Munro every day for 13 days in a row, then you're starting to understand what this trek involves.
How tough is the terrain?
Many parts are what our guide described as “a little bit technical”. There were several days that involved scrambling over difficult terrain (including slabs which are notoriously slippery when wet, and scree slopes covered in loose rocks) while exposed to big drops.
Some of these sections were protected by fixed chains, but many weren’t, and a slip would have been more than problematic. You need to be comfortable moving across this sort of terrain. Oh, and you'll be doing all this with a sizeable pack on your back.
What gear do I need to carry in my pack?
Despite being an island in the sunny Mediterranean, the Corsican mountains get some brutal weather. The thunderstorms are infamous and temperatures can plummet.
You’ll need the same clothing you would when hiking in the UK. But because when the sun does come out it turns the Corsican mountains, particularly the lower elevations, into a baked sun trap, you’ll also need to carry a lot of water.
I started each day carrying at least 3 litres, and drank it all, often topping it up from springs along the way. That’s 3kg right there. And if you’re pale like me, you’ll also need vast quantities of suncream. Then there’s your overnight kit; sleeping bag, mat, change of clothes, toothbrush, that sort of thing.
And food – possibly some communal snacks to share with the group. And definitely don't forget your camera.
Where will I sleep each night on the GR20?
It’s a real mixed bag. The GR20 stays high in the mountains for days at a time. During these stages we stayed at mountain refuges. We actually slept in tents outside the refuges, which tend to be quieter and more private than dorm rooms, and also less plagued by bed bugs.
The evening meals at the refuges were pretty good, the provided packed lunches substantial, but the breakfasts… limited. Jam spread directly onto slightly stale bread using a wooden coffee stirrer is not the breakfast of champions. The smart folk had brought instant porridge sachets with them.
Some nights, when the trail dips to relative civilisation, we stayed in a gite, where food was a marked improvement. Needless to say, on both the refuge campsites and in the gite dorm rooms, sleep wasn’t always easy to come by.
What are the highlights of walking this trail?
The GR20 might be one of the toughest treks in Europe, but it’s also one of the most beautiful in the world. The mountains of Corsica are seriously stunning, and I wasn't prepared for just how much they and the surrounding landscape would vary throughout the trek.
And not just the views – it was a near constant assault on all the senses; the ever-changing colours of the rock, transitioning from grey to red and glowing in the sunrise and sunsets; the vast swathes of greenery of every shade emanating from the native forests swaddling the hillsides; the calls of birds, the rutting deer, the grunts of the wild pigs, and the echoing ring of unseen cowbells high in the mountains.
And the smells! Oh, the smells. The rich herbal scents of the maquis shrubland – a heady mix of eucalyptus, juniper, rosemary, heather, myrtle, sage, mint, thyme, lavender and more – is said to notify Corsican sailors of their nearing home long before they can see the island.
Corsica’s most famous sailor, Napoleon Bonaparte, is said to have claimed he could smell the maquis, even while he was exiled on Elba. Even the super-strong Corsican cheeses made by the shepherds at their mountain bergeries grows on you after a while…
Any non-smell related highlights?
Oh, almost too many to mention. Where do I begin? The first big mountain view from Bocca a u Saltu (bocca translates as 'mountain pass'). Thrilling suspension bridges. Even bigger mountain views at Bocca di a Muvrella.
Befriending donkeys. Lying in a tent while a Corsican thunderstorm erupts overnight, creating morning rivers that weren’t there the day before. Soaring red kites and tame white horses at Lac de Nino. Sunrise over the twin lakes of Lac de Melo and Lac de Capitello from Bocca Alle Porta.
Singing along to Bella Ciao at a refuge-cum-disco high in the mountains. Messing around in magical wild swim spots. Close-up encounters with Tyrrhenian Lizards and Corsican Fire Salamanders. Dappled forests, ancient trees, and mist-hazed waterfalls.
Sunrise over the sea from Bocca ‘Oru. Sunset over a sea of clouds from Bocca di Suragheddu, shared with good company and a glass of mirto, a traditional Corsican liqueur made from the berries of the myrtle. The red peaks of Bavella by dawn. Need I go on?
How do I plan my own GR20 trip?
There are advantages to trekking the GR20 self-supported. You can choose your own itinerary, and you won’t have to worry about how your fitness compares with the rest of a group. But although the route is well way-marked and manageable solo by experienced hikers, there are many advantages to a guided trek.
A group tour will sort the logistics of accommodation and luggage transfers, meaning all you have to worry about is walking and enjoying. Prior to the trip you’ll get useful details like comprehensive kit lists and training suggestions. But the real benefits come on the trek itself.
A guide provides information about the history, environment, and wildlife that you never knew you wanted to know. They will show you secret places like hidden swimming spots and epic viewpoints. They’ll smooth the process of refuges where the guardians may speak little English and can often be a touch ‘spikey’.
They’ll have access to the most recent weather reports and can make the difficult decisions regarding route choices and timings to avoid the Corsican thunderstorms. And, if something should go wrong, they’ll be on hand to sort everything.
I trekked with GR20 with KE Adventure, the Keswick-based experts in adventure holidays. They use a local agent on the island and our guide on the GR20 was the magnificent Paulin. He was highly knowledgeable and overflowing with passion for Corsica. It felt like being shown the mountains by a good friend who was happy to share all that he knew and spread his love of the landscape.
The final potential advantage of a group is the group. I got lucky and shared by GR20 experience with an amazing bunch of fellow trekkers. We laughed, we cried, we swore more than is decent, and we bonded over an incredible shared experience. With that in mind, huge thanks must go to Nick, Lisa, Megan, Grace, Pauline, Alastair, Julie, Sarah and Dave for helping to make the trek extraordinarily good.
To find out more about KE Adventure’s ‘GR20 Corsica - The Complete Route’ (along with the wealth of other trips, destinations and activities on offer), visit keadventure.com/GR2
How do I prepare for trekking the GR20?
We've established that you'll be trekking for 13 days, covering an average of around 14km distance and nearly 1000m of ascent every day while negotiating tricky terrain with a heavy pack on your back – how on earth do you prepare?
The truth is you can't. At least, not for all of it in one go. But get used to walking uphill. A lot. Then get used to walking downhill. Also a lot. Ensure you’re confident on scrambling terrain, on loose screes, and with airy exposure. Become comfortable with the weight of a heavy pack (it has a notable effect on your balance).
But most importantly, be as fit as you possibly can. Make time to make the effort. It'll all be worth it once you're in Corsica, and for two important reasons.
Firstly, you want to be sure you're capable of completing the trek. This may sound harsh, but if your lack of fitness or ability means it’s not safe (or not fair on the group) for to you to continue you will be required to drop out.
And this brings us on to the second reason. Any group is limited by its least fit members. While you certainly won't be left behind if you're physically capable of completing the trek, you don't want to be the reason the group as a whole gets caught in a late afternoon thunderstorm, or misses sunrise at a breathtaking viewpoint, or has to skip a spectacular high-level mountain route to take a low-level bypass, all because you can't keep up with the pace.
Is there any special kit I need to take with me?
When it comes to footwear, go for comfort, light weight, and scrambling ability (particularly on slabs) over robustness and protection.
Take more loo roll than you think you’ll need and keep a bottle on alcohol gel on you at all times. Instant porridge sachets boost the limited breakfasts, and taking a set of stowable cutlery means you won’t have to eat with your fingers.
Do pack a sleeping mat (the refuge provided ones aren’t great), buy your GR20 related souvenirs at Haut Asco at the end of day 3 (the best selection by far), and, for the love of all that is holy, invest in some ear plugs; between the late night helicopters, the early morning generators, the insomniac mules, and the cacophony of snores that is a dorm room, you’ll need them.
What guidebooks and maps would you recommend?
Trekking the GR20 by Paddy Dillon: A superb guidebook that provides all the information you need to tackle the GR20. Even if you’re on a guided trip, the detailed descriptions of the stages, the hints and tips, and the appetite whetting photos make the guide worth tucking in your pack, while the pull-out map book is great for keeping track of where you’ve been and where you’re going.
IGN Top 25 series maps: While not essential on a guided trip (your guide will be carrying them), if you’re the kind of hiker to likes to pore over maps of the wider area before you head off, or study them afterwards to learn more, these maps are worth having. If you’re travelling solo, they’re essential. You need 4 to cover the whole GR20: 4250 OT, 4251 OT, 5252 OT, and 4253 ET.
Asterix in Corsica: Will it help you walk the GR20? No. Will it give you a bit on an insight into Corsican history and culture? Maybe. Is it a fun read? Oh yes. You can pick up a copy secondhand for next to nothing from various websites, and it’s on sale almost everywhere in Corsica – albeit in French.
Any final tips before I book my trip?
The GR20 is beautiful and tough in equal measure. But prepare properly, have the right kit, and go into it with your eyes open (and your ears protected), and it might just be one of the best things you'll ever do.
CLICK HERE for detailed guides in our collection of the UK's very best walking routes, which are not only great walks but will help you prepare for big overseas treks like the GR20.
About the author
Ben Weeks is Trail magazine's gear editor and has travelled all over Britain and Europe on his mountain adventures. Ben's winter climbed in Scotland, scrambled the Polish Tatras, summited Alpine peaks and Kilimanjaro, and loves via ferrata in the Dolomites, but still counts the GR20 as one of his all-time top mountain experiences.
