The Hiking World

GR20

Frà li monti

OSM hiking route on Corsica's granite spine (183.6 km line), Calenzana to Conca. Vertical figures sampled from Copernicus GLO-30. Days (15) is a placeholder from round(lengthKm/12), not the published 14–16 day window (unverified).

Byline

  • The Hiking World editorial · author

    Desk byline for seed records. Named surveying editors replace this once a trail is verified.

GR20 between Carozzu and Asco, Corsica
Photo: MartinThoma · CC0 · Wikimedia Commons

Figures marked provisional are seed data and still need verification. Source and last-checked date sit under each cited value.

loading map...
Facts42.508, 8.855
Distance183.6 km*
osm:relation:12484370 · 2026-08-24 · osm · provisional
Ascent+12,361 m*
copernicus-dem:glo-30 · 2026-08-24 · dem · provisional
Descent12,378 m*
copernicus-dem:glo-30 · 2026-08-24 · dem · provisional
High point2,589 m*
copernicus-dem:glo-30 · 2026-08-24 · dem · provisional
Low point254 m*
copernicus-dem:glo-30 · 2026-08-24 · dem · provisional
Routepoint-to-point
Days15
Season16 May–4 Oct (PNRC refuge-warden season 2026)
GradeSAC T2 · YDS 1

Editorial v1 · Provisional catalog

DifficultyUngraded (OSM ingest)
SAC T2
Mountain hiking. Continuous trail, some steep ground, sure-footedness helpful.
YDS Class 1
Class 1. Walking on an established path; low fall risk.
Wikidata Q262374

Log in to view the elevation profile

Ingested from OpenStreetMap relation 12484370 (ODbL). The mapped line and 2D length are derived from that geometry. Ascent, descent, and high/low points are sampled from Copernicus GLO-30 (copernicus-dem:glo-30) and remain provisional. Water, permits, and hazards were not taken from OSM tags and must be verified.

OSM 2D length is 183.6 km (relation 12484370; GR 20 Principale, red/white nwn, Wikidata Q262374). Endpoints are Calenzana (fontaine San'Antone / OSM line start) to Conca. Yellow-dot difficult variants are separate OSM relations (1771390 Monte Incudine; 9627013 Variante Alpine Onda–Vizzavona) and were not fetched. Published 179–180 km / 14–16 days (PNRC Frà li monti, https://www.pnr.corsica/fr/randonnees-decouverte/gr-20-fra-li-monti, checked 2026-08-24; Wikipedia GR 20 infobox 180 km, https://en.wikipedia.org/wiki/GR_20, checked 2026-08-24, CC BY-SA) are cross-checks only, not this DataPoint.

DEM high 2,589 m sits in the published high-pass band (~2,000–2,600 m). GLO-30 cumulative ascent 12,361 m is in the same order as Wikipedia's 12,000 m gain (same page, checked 2026-08-24); a ~28,000 m published lead is a cross-check only and is not this DataPoint. High point left as Copernicus.

typicalDays 15 is Math.round(lengthKm/12), a placeholder. Published thru-hike windows are 14–16 days; that stamp is not this field. PNRC calls this one of Europe's hardest waymarked trails — the ingest grade was not overwritten.

Water was not mapped to named WaterSource points (no honest atFraction). PNRC notes refuge running water and stage springs; they were not positioned from an official named list this pass.

Water

No water sources recorded.

Permits & fees

No permit required.

Getting there

Sourced legs to the Calenzana (OSM line start) base start station — where this trail record begins. This is not a route planner: durations are approximate and marked provisional until an official transport page confirms them.

  1. Road · Calvi Sainte-Catherine (CLY) → Calvi

    Calvi airport is the closest air gateway to the GR20 northern trailhead (https://en.wikipedia.org/wiki/Calvi_%E2%80%93_Sainte-Catherine_Airport, checked 2026-08-24).

    en.wikipedia.org · 2026-08-24 · wikidata · official · provisional

  2. Rail · Bastia Poretta (BIA) → Calvi

    Bastia is the other advertised Corsican gateway (https://en.wikipedia.org/wiki/Bastia_%E2%80%93_Poretta_Airport, checked 2026-08-24). Continue to Calvi by the island railway or bus, then road to Calenzana.

    en.wikipedia.org · 2026-08-24 · wikidata · official · provisional

  3. Road · Calvi → Calenzana

    PNRC: the GR20 starts in Calenzana at the fontaine de San'Antone (https://www.pnr.corsica/fr/randonnees-decouverte/gr-20-fra-li-monti, checked 2026-08-24). Local bus or taxi from Calvi; no rail to the village.

    pnr.corsica · 2026-08-24 · official · provisional

No rail to Calenzana. PNRC forbids GR20 departures from Calenzana after 11:00 in the fire-risk season (checked 2026-08-24).

Plan from your location

Type a city, then pick a match. These links open external search tools — they do not fetch fares or timetables.

Trailheads

  • Calenzana (OSM line start) car-free: unknown
  • Conca (OSM line end) car-free: unknown

Log in to view trailhead transit detail

Hazards

  • Exceptionally strenuous technical alpine walking: PNRC notes steep, narrow, and slippery sections and, in places, rappel descents (https://www.pnr.corsica/fr/randonnees-decouverte/gr-20-fra-li-monti, checked 2026-08-24). Hands may be needed from stage 1. The ingest difficulty grade was not forced.
  • Summer heat and fire risk: from mid-June to mid-September massifs can close with the weather; no GR20 departure from Calenzana after 11:00; smoking and fires banned in forests 15 June–30 September (same PNRC page, checked 2026-08-24).
  • Rapid mountain weather including violent summer thunderstorms (PNRC mountain-safety notes, same page, checked 2026-08-24).
  • Wild camping is prohibited; camping only next to refuges or on marked bivouac areas (municipal orders on the same PNRC page, checked 2026-08-24).
  • The Cirque de la Solitude / E Cascettoni is closed after the 10 June 2015 rockfall; the official GR20 uses the FFRP diversion (same page, checked 2026-08-24).