Challenge

GR20 Corsica

Corsica, France

About this challenge

The GR20 is Europe's most challenging and spectacular long-distance hiking trail, traversing 180 kilometers along Corsica's rugged granite mountain spine from Calenzana in the north to Conca in the south. This legendary route demands 12-16 days to complete, with 12,000 meters of total elevation gain through some of the Mediterranean's most dramatic wilderness terrain. The trail showcases Corsica's diverse ecosystems, from Mediterranean maquis scrubland to alpine meadows, while passing pristine mountain lakes, exposed granite ridges, and the island's highest peaks. The northern section features technical scrambling and knife-edge traverses requiring hands-on climbing skills, while the southern portion offers gentler gradients through forested valleys with opportunities for mountain swimming.

Quick facts

Checkpoints: 13
Distance: 180 km
Avg Completion: 12-20 days
Best Season: Anytime

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Overview

The GR20 is Europe's toughest long-distance hiking trail, cutting through the granite backbone of Corsica from Calenzana in the north to Conca in the south. This legendary trail spans 180 kilometers with 12,000 meters of elevation gain, attracting around 10,000 to 20,000 hikers annually who typically complete it in about 15 days. The trail is officially divided into 16 stages, though hikers often combine or split these based on fitness and weather conditions. The route follows the granite backbone of mountains that divide the island in two, many of which soar above 2000m altitude. The northern section from Calenzana to Vizzavona presents the most technical challenges with exposed ridges, knife-edge traverses, and steep scrambles requiring hands-on climbing. The southern section, while still demanding, offers gentler gradients through forested valleys with opportunities for mountain pool swimming. Corsica's mountain culture runs deep along this trail, connecting hikers with centuries-old pastoral traditions. The path passes traditional stone shepherds' huts called bergeries and follows ancient transhumance routes where shepherds moved their flocks between seasonal grazing areas. This cultural heritage adds meaning to the physical challenge, representing the island's connection to mountain life and self-sufficient highland communities.

History and Geology

The GR20 was conceived by former general inspector for youth and sports Marcel Schlück and his friend Guy Degos, both hiking enthusiasts. The trail was conceived by Michel Fabrikant back in 1970, representing a successful effort to preserve Corsican mountain heritage while promoting sustainable tourism. The development involved collaboration between local communities, hiking associations, and the French National Park Service to create infrastructure while protecting fragile ecosystems. The western range of Corsica's mountains is made up of volcanic rocks such as rhyolites, ignimbrites and granite, also called terra di signori (land of lords) or "Above the mounts". The island's geological foundation formed 300 million years ago through massive granite intrusions, creating today's dramatic peaks and deep valleys. These ancient formations weather into distinctive rounded boulders, narrow ridges, and vertical cliff faces that define the GR20's challenging terrain. Glacial activity during ice ages carved spectacular cirques, moraines, and U-shaped valleys visible throughout the route. Tortured granite formations line sections like the Arête a Monda, also known as the Arête des Statues, where steep couloirs are sometimes equipped with chains. This geological diversity creates both the technical challenges and stunning scenery that make the GR20 uniquely demanding among European trails.

Safety

Essential gear must handle Mediterranean heat, sudden mountain storms, and potential snow conditions even in summer. Weather protection requires waterproof jackets and pants for frequent weather changes, plus layering systems for extreme temperature variations from sea-level heat to alpine conditions above 2,000 meters. Technical equipment includes sturdy hiking boots with ankle support, trekking poles for steep rocky descents, and lightweight mountaineering gear for exposed sections. Navigation benefits from excellent waymarking with red and white paint blazes every 20-50 meters, though weather can obscure markers during storms or fog. Carry detailed IGN topographic maps, compass, and GPS devices alongside comprehensive first aid supplies, emergency shelter, headlamp with extra batteries, and emergency whistle for remote terrain. Sun protection becomes critical at high elevation where UV radiation reflects off granite and snow fields. The GR20 presents serious mountain safety challenges combining extreme physical demands with technical terrain and rapidly changing weather. The northern section requires scrambling skills with exposure to significant fall hazards, while lightning danger increases at high elevation during afternoon thunderstorms. Emergency evacuation proves extremely difficult and expensive from remote locations, making comprehensive insurance coverage essential. Helicopter rescue may be the only option for serious injuries in areas without cellular coverage.

Nutrition and Other

Mountain refuges positioned 4-8 hours apart provide basic dormitory accommodation, meals, and essential supplies, eliminating heavy camping equipment for most hikers. Refuge fees typically range from 15-25 euros per night for dormitory accommodation, with meals additional. Advance reservations are essential during peak season (June-September) through the Corsican National Park Service. Camping is permitted near most refuges in designated areas for 5-10 euros per night, though wild camping is strictly prohibited except in emergencies. Food planning focuses on lightweight, high-energy nutrition for demanding mountain conditions. Most refuges provide meals and basic supplies, allowing hikers to minimize pack weight while ensuring adequate nutrition for 8-12 hour hiking days. Essential trail foods include energy bars, nuts, dried fruits, and electrolyte supplements for hot weather. Water management varies along the route, with reliable sources at refuges and camping areas, plus excellent mountain streams and springs throughout most sections. The GR20 requires no special permits for hiking, though accommodation and camping fees support trail maintenance and environmental protection. National park regulations require following Leave No Trace principles, staying on designated trails, and respecting wildlife protection areas. Violations can result in significant fines. The optimal season runs from mid-June through September when high-altitude snow has melted and refuges operate at full capacity, with July and August offering the most stable weather but highest temperatures and crowds.

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Featured checkpoints

Calenzana to Ortu di u Piobbu

Calenzana, 20214 Calenzana, France

11 km

Ortu di u Piobbu to Carozzu

Carrughju Di U Piobbu, 20290 Lucciana, France

Carozzu to Ascu Stagnu (Haut-Asco)

Calenzana, Haute-Corse, France

Tighjettu to Ciottulu di i Mori

Albertacce, Haute-Corse, France

7 km

Ascu Stagnu to Tighjettu

Stagno, 20276 Asco, France

9 km

Ciottulu di i Mori to Petra Piana

Corsica, France

All stops on this route

GR20 Corsica: common questions

How long is GR20 Corsica?

GR20 Corsica covers 180 km in total.

How long does GR20 Corsica take to complete?

Most people complete GR20 Corsica in about 12-20 days.

When is the best time to do GR20 Corsica?

The best season for GR20 Corsica is Anytime.

How many checkpoints does GR20 Corsica have?

GR20 Corsica has 13 checkpoints to log on the way to finishing it.