A trail that ranks before it tells a story
On the map of France's GR trails, few sections carry as unanimous a reputation as the GR20 North. Corsican mountain guides and guide bureaus agree on one thing: the northern half of the crossing, from Calenzana to Vizzavona, concentrates most of the GR20's most committing passages — tilted slabs, handrails, ridges exposed to drops on both sides. This is not a trail you improvise after a few weekends of lowland walking.
This guide does not cover the GR20 as a whole — another article on the site takes a more narrative approach to that. It is written for those concretely preparing this northern section: nine days, roughly 97 to 100 km, and a cumulative elevation gain that far exceeds most mid-mountain GR trails over an equivalent distance. The difficulty comes less from the length of the stages — often short on paper — than from their sheer verticality and the commitment they demand from the moment you step out of each refuge.
Nine stages, one common thread
From Calenzana, the trail climbs without transition toward the Ortu di u Piobbu refuge: more than 1500 meters of elevation gain packed into a single morning, under a sun that hits the pale slabs early. Two days of ridgelines and cables follow, leading to Carrozzu, then the crossing of the Spasimata footbridge, suspended above its canyon, before the tilted slabs that climb to Asco Stagnu.
The turning point of the route comes on the fourth day. The former Cirque de la Solitude, now closed, is bypassed via the alpine Pointe des Éboulis variant, which skirts Monte Cinto above 2600 meters — without reaching its summit, which tops out at 2706 meters, the highest point in Corsica — before descending toward the mineral landscape of Tighjettu. The rest of the route follows the upper Golo valley and its emerald pools, passing the Ciottulu di i Mori refuge and then Manganu.
Contrary to popular belief, the trail doesn't wrap up there in one final leap to Vizzavona: two more days and two more high-altitude refuges still separate the walker from the forest. From Manganu, the trail climbs to the Petra Piana refuge, perched on its granite spur at the foot of Punta Muratello, then reaches L'Onda the next day, tucked into a greener valley. Only at the end of a ninth and final stage — long and grueling — does the trail finally descend toward the shaded forests of Vizzavona.
"On the GR20 North, Corsica doesn't line up one summit but eleven, like a bill to be settled ridge after ridge."
Day-by-day itinerary
| Day | Stage | Distance | Ascent / Descent | Estimated time | Accommodation |
|---|---|---|---|---|---|
| 1 | Calenzana → Ortu di u Piobbu | 10 km | 1600 m / 150 m | 6h30 | Ortu di u Piobbu refuge |
| 2 | Ortu di u Piobbu → Carrozzu | 8 km | 500 m / 950 m | 5h30 | Carrozzu refuge |
| 3 | Carrozzu → Asco Stagnu (Spasimata footbridge) | 11 km | 950 m / 700 m | 6h30 | Asco Stagnu gîte d'étape |
| 4 | Asco Stagnu → Tighjettu (Pointe des Éboulis variant, Monte Cinto) | 15 km | 1450 m / 1150 m | 9h30 | Tighjettu refuge |
| 5 | Tighjettu → Ciottulu di i Mori (Golo valley) | 13 km | 900 m / 800 m | 7h00 | Ciottulu di i Mori refuge |
| 6 | Ciottulu di i Mori → Manganu | 14 km | 750 m / 900 m | 7h30 | Manganu refuge |
| 7 | Manganu → Petra Piana | 8.4 km | 820 m / 600 m | 6h30 | Petra Piana refuge |
| 8 | Petra Piana → L'Onda | 10 km | 450 m / 855 m | 4h50 | L'Onda refuge |
| 9 | L'Onda → Vizzavona | 10.3 km | 675 m / 1200 m | 6h30 | Vizzavona gîtes and hotels |
These walking times assume a reasonably light pack and fair weather; they can vary significantly depending on conditions, the group's fitness, and the state of the terrain after a snowy winter — particularly on the high-altitude variant of day 4.
Preparing your crossing: dates, gear, refuges
The most favorable window runs from mid-June to mid-September. Outside these dates, snow can still block the high-altitude variant around Monte Cinto late in the season, or blanket it again with the first snowfalls of September. Even in the height of summer, afternoon thunderstorms are common in Corsica, making it essential to start each stage early and keep an eye on the sky from early afternoon onward.
On gear: aim for a pack around 10 to 11 kg without food, sturdy boots with a rigid sole and strong grip, and a water capacity of at least 3 liters — springs become scarce at altitude, particularly on the section between Asco Stagnu and Tighjettu.
On camping: wild camping is banned across all of Corsica. Bivouacking is tolerated only in the immediate vicinity of certain refuges, on designated sites whose number, exact location, and booking rules are set by the Parc Naturel Régional de Corse (PNRC) and may change from one season to the next. It's best to check these rules on the PNRC's official website before setting off, rather than relying on any account, however recent.
On the route's most talked-about passage: the Cirque de la Solitude remains closed at the time of writing, and the alpine variant that bypasses it via the Pointe des Éboulis is itself a committing route, sensitive to snow conditions and rockfall. Checking its status with the PNRC or refuge wardens before setting out remains essential, rather than relying solely on the route described here.
For resupply, most of the refuges along the way offer a small emergency shop and hot meals, which helps lighten the initial load. Stock and opening hours vary, however, depending on how busy the trail is and the time of season: keeping a spare day's worth of food is a reasonable precaution in case of weather delays, particularly on the high-altitude stages toward the end of the route (Petra Piana, L'Onda).