Hiking the GR20 Trail in Corsica, North to South

The northern half is the harder one. Stages are long, the rock is steep and the trail often uses chains, fixed handholds and boulder fields rather than a path. The first nights pass the refuges of Ortu di u Piobbu and Carrozzu, where a suspension footbridge crosses the Spasimata gorge above smooth granite slabs.

Haut Asco is a small ski station at the head of a valley, with a hotel and a road, the only real contact with civilisation on the northern half. From here the old route crossed the Cirque de la Solitude, a sheer gully descended on chains. On 10 June 2015, a rockfall there killed seven hikers, and the official GR20 was moved. The trail now climbs over the Pointe des Éboulis, at around 2,600 metres the highest point on the route, before dropping to the Tighjettu refuge. The ascent from Haut Asco is long and steep, over loose scree, and it starts best at first light. Strong walkers sometimes add the summit of Monte Cinto, at about 2,700 metres the highest peak on the island.

Beyond Tighjettu, the trail passes beneath Paglia Orba, a striking peak often compared to the Matterhorn, and down to the road pass of Col de Vergio. Lac de Nino comes next, a mountain lake surrounded by pozzines, spongy grass meadows threaded with small pools where wild horses graze. It is one of the gentlest moments of the walk.

The stretch from the Manganu refuge to Petra Piana includes the Brèche de Capitellu, a notch in the ridge reached by a steep climb, with a drop on the far side to two glacial lakes, Capitello and Melo. The final northern stages pass the Onda refuge and the slopes of Monte d’Oro before descending through beech and pine forest to Vizzavona.

Vizzavona is a hamlet in the forest with a railway station, a few hotels and shops. Many hikers walk only one half of the route, and this is where they start or finish. The station sits on the line between Ajaccio and Bastia, served by the small trains locals call the trinighellu, which wind slowly through tunnels and over viaducts across the island’s interior.

On the station platform, hikers coming off the northern half can be recognised at once. Their boots are scuffed white by granite, and many head straight for the café.

Walkers on the northern half share the ridges with animals that rarely see a road. Corsican mouflon, wild sheep with heavy curled horns, live on the high slopes and are most often spotted at dawn, though they keep their distance. Semi-wild pigs root about in the chestnut woods lower down, and cows wander the meadows around Lac de Nino and Col de Vergio with no apparent owner. Overhead, the island is one of the last places in France outside the Pyrenees and the Alps with bearded vultures, huge birds that feed on bone, and a pair circling a ridge is a sight hikers talk about at the refuge that night.

The sheep and goats are not wild. Shepherds still move flocks up to summer pastures, and their stone bergeries, some of them centuries old, are scattered along the route.

The southern half begins gently in forest of pine and beech, with more springs and fewer chains. Stages are shorter. The trail rises to open ridges around the Capannelle and Prati refuges, where the views open on both coasts on a clear day.

Monte Incudine, at about 2,100 metres, is the highest point of the southern half and is crossed on the route. The descent from it to the Asinau refuge is steep and long, and is one of the hardest days in the south.

The highlight for many hikers is Bavella, where pinnacles of red granite rise above pine woods. The trail splits here: the standard route goes around the needles, and an alpine variant crosses between them on a narrow ridge with chains and exposed sections, usually in fine weather only. On the final day, the path drops through maquis and oak woodland towards Conca, a village a few kilometres from the coast, and the end of the GR20 is marked by a sign and, in season, a café terrace full of hikers comparing blisters.

The refuges along the GR20 are run by the Corsica Regional Natural Park. Each has a hut with bunks, a kitchen area, a water point and space for tents. In the guarded season, roughly mid-May to early October, booking is mandatory, including for tent pitches. The park opens its online reservations early in the year, and nights at some popular refuges sell out within days. Outside the season the refuges are unguarded, and the route turns into a serious mountain undertaking.

Wild camping along the trail is not permitted. Tents may only be pitched near the refuges.

Many refuges sell basic meals, drinks and supplies, and several shepherds’ bergeries along the route sell cheese and charcuterie. Brocciu, a fresh ewe’s and goat’s milk cheese, turns up in omelettes, pastries and on bread. There are no cash machines on the trail, and card payment is not always possible, so cash is still worth carrying.

The guarded season sets the window, but conditions within it vary widely:

• May and early June: snow often remains on north-facing slopes and high passes in the northern half, and some sections may be dangerous without experience on snow.
• Late June: long days, flowers and more stable weather; often the best compromise.
• July and August: hot and busy, with afternoon thunderstorms in the mountains. Starting at dawn and finishing by early afternoon is common practice.
• September: cooler, clearer and quieter, with shorter days.

Weather changes quickly in the Corsican mountains. Fog can hide the waymarks on the ridges, and storms bring lightning and strong winds. Refuge wardens post forecasts and advise on whether to continue.

Weight decides how much the GR20 hurts. Hikers who sleep in the refuges and buy most meals along the way can walk with a pack of around ten kilograms; those carrying a tent, stove and a week of food may double that, and on the scrambles of the northern half every extra kilo is felt in the arms as much as the legs. Boots or trail shoes with a firm sole matter more than anything else, because the granite is coarse and the scree is loose. Trekking poles help on the long descents. A waterproof jacket and a warm layer are needed even in August, as temperatures on the high passes can drop sharply when a storm comes through.

The trail is waymarked in red and white paint, but a map or a downloaded track is still essential in fog. Mobile coverage is patchy in the mountains, and refuge wardens are often the only source of weather information for days.

The GR20 needs no technical climbing gear, but it does need fitness and steady nerves. Most stages involve six to eight hours of walking, with steep ascents and descents, and several days require scrambling on exposed rock. Hikers who have done a hard mountain day such as New Zealand’s Pouakai Crossing on Mount Taranaki will have a sense of the terrain, but the GR20 repeats that effort day after day for two weeks.

If you are unsure, walking only the southern half is a sensible way to start. Some hikers use guided or self-guided packages, in which a local company books refuges and transfers, and some arrange for luggage to meet them at road access points.

For runners and walkers who like mountain events, the GR20 shares something with the Jungfrau Marathon in the Swiss Alps: an effort that stays in the legs long after the finish line.

Corsica has airports at Bastia, Calvi, Ajaccio and Figari, and ferries from mainland France and Italy reach Bastia, Ajaccio, Calvi and other ports. Ferries from Nice and Toulon also make it possible to combine the GR20 with a few days on the Riviera, including Monaco and Monte Carlo. Calenzana is reached by bus or taxi from Calvi. Conca is linked to Porto-Vecchio, and from there buses run to Bastia and Ajaccio. Mid-route, Vizzavona is the simplest entry or exit point because of its railway station. More route guides are collected in the travel guides section.

Transport out of Conca is limited, especially early and late in the season, so the onward ride to Porto-Vecchio is worth arranging from the last refuge, where wardens usually know who runs the shuttle that year.