GR20: 16 stages and when to book
Calenzana to Conca along the crest of Corsica: sixteen days of rough granite, hands-on scrambling and big daily climbs, refuge to refuge. Widely called the hardest of Europe’s classic long trails, and one of the most spectacular.
Start: Calenzana. Finish: Conca.
The 16 stages
| Day | Stage | Distance | Climb |
|---|---|---|---|
| 1 | Calenzana → Refuge d'Ortu di u Piobbu | 11 km | 1,914 m |
| 2 | Refuge d'Ortu di u Piobbu → Refuge de Carrozzu | 7.1 km | 823 m |
| 3 | Refuge de Carrozzu → Ascu Stagnu (Haut Asco) | 4.6 km | 953 m |
| 4 | Ascu Stagnu (Haut Asco) → Refuge de Tighjettu | 7.8 km | 1,414 m |
| 5 | Refuge de Tighjettu → Refuge de Ciottulu di i Mori | 6.2 km | 810 m |
| 6 | Refuge de Ciottulu di i Mori → Refuge de Manganu | 24.4 km | 1,412 m |
| 7 | Refuge de Manganu → Refuge de Petra Piana | 8 km | 1,027 m |
| 8 | Refuge de Petra Piana → Refuge de l'Onda | 9.6 km | 565 m |
| 9 | Refuge de l'Onda → Vizzavona | 10 km | 832 m |
| 10 | Vizzavona → Gite U Fugone (E Capanelle) | 13.7 km | 1,622 m |
| 11 | Gite U Fugone (E Capanelle) → Refuge de Prati | 17.2 km | 1,613 m |
| 12 | Refuge de Prati → Refuge d'Usciolu | 10.3 km | 930 m |
| 13 | Refuge d'Usciolu → Bergeries de Matalza | 10.4 km | 532 m |
| 14 | Bergeries de Matalza → Refuge d'Asinau | 9.5 km | 740 m |
| 15 | Refuge d'Asinau → Refuge de Paliri | 14.7 km | 1,159 m |
| 16 | Refuge de Paliri → Conca | 12.7 km | 685 m |
The line is assembled from OpenStreetMap and measured continuous. Elevation, ascent and times are computed, not recorded on the ground.
Book these first
Refuges are run by the Parc naturel régional de Corse and booked through its central reservation system at pnr-resa.corsica.
- Refuge de Carrozzu
- Refuge de Ciottulu di i Mori
- Refuge de Paliri
A refuge booking covers a bunk, a bivouac pitch or tent hire, chosen at reservation.
July and August book out well ahead. Reserve the whole chain before committing to dates.
When to go
Refuges are staffed roughly June to late September. Snow can hold the northern high sections into June; July and August bring heat and full refuges.
- JanuaryWinter in the Corsican mountains
- FebruaryDeep winter
- MarchStill winter above 1,500 m
- AprilSnow holds the high route
- MayEarly birds with alpine kit
- JuneSeason opens properly
- JulyPeak season, peak heat
- AugustHigh season
- SeptemberArguably the best month
- OctoberClosing time
- NovemberAutumn storms, first snow
- DecemberWinter
The GR20 in Treksup
The GR20 is a paid route in Treksup: its full plan, with every stage, water, the refuges and weekly trail conditions, comes with the paid tier. Seven routes are open in full for free.
See Treksup on the App StoreGR20 2027: when the refuge bookings open, and how to book the chain →
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Page updated 29 September 2026.