Stages
Which is the hardest stage of the GR20?
Which is the hardest stage of the GR20? Every hiker asks the question before setting off — and there is no single answer. Depending on whether you mean raw effort, alpine terrain or the shock of day one, three stages compete for the title. Here is our ranking of the 16 official stages, backed by the numbers.
The ranking
The 5 hardest stages
Our method — the same one behind the site's planner — adds elevation, distance and technicality for each stage. On raw effort, stage 6 (Ciottulu di i Mori → Manganu) comes first: at 24.8 km, it is by far the longest day on the route. Many hikers, though, name stage 4 (Ascu Stagnu → Tighjettu) as the hardest: the most alpine of all, climbing to the GR20's high point at 2,607 m over scree and a bare ridge. Others point to stage 1 and its +1,376 m of ascent swallowed on day one, with no warm-up. All three answers hold: it depends on what hurts you most — your legs (stage 6), the terrain and the drops (stage 4), or the lack of any easing-in (stage 1).
1 · Ciottulu di i Mori → Manganu Stage 6 →
24.8 km: the longest stage of the official route — nothing else comes close. The elevation stays moderate (+692 m, -1,082 m), but the distance does the damage. The trail passes Castel di Vergio — an emergency top-up point, not a real resupply — then skirts Lac de Nino and its pozzines before reaching Manganu. A full day of walking where fatigue builds kilometre after kilometre, with no major technical section, but no respite either.
2 · Calenzana → Ortu di u Piobbu Stage 1 →
+1,376 m, the biggest single climb on the GR20, for just -131 m of descent over 10.9 km. And it lands on day one, with no warm-up: you leave Calenzana, the last proper resupply for several days, on legs that are not yet trail-hardened. The ascent is steady and relentless on stony ground, with strong sun exposure by late morning. Starting early makes a real difference on the lower section.
3 · E Capannelle → Prati Stage 11 →
17.6 km, +837 m, -644 m: the longest day in the southern half. Beyond E Capannelle the route settles onto the southern ridges, where afternoon storms are hard to manage — start early. Less technical than the north, this stage wears you down by accumulation: distance and climbing stack up across a day that never seems to end. It catches out hikers convinced the hard part stops at Vizzavona.
4 · Ascu Stagnu → Tighjettu Stage 4 →
Only 8.3 km, but +1,161 m and -916 m: the densest stage of the GR20. It is also the most alpine: from Ascu Stagnu the trail climbs to Pointe des Éboulis, the route's high point at 2,607 m, up a steep, mineral ascent over scree and ridge — the itinerary opened in 2016 after the Cirque de la Solitude closed. Airy, but with no actual climbing; the long descent to Tighjettu closes out a demanding day. Many walkers call it the hardest of all.
5 · Vizzavona → E Capannelle Stage 10 →
13.8 km and +938 m for only -269 m: an almost uninterrupted climb. This is the restart after the Vizzavona break, and that is exactly what makes it treacherous — the rhythm has slackened, and the GR20 immediately demands the best part of a thousand metres of ascent. Nothing technical stands in the way, just a long, steady effort proving that the southern half, supposedly gentler, still has to be earned.
The other angle
What about exposure and terrain?
If exposure worries you more than effort, the ranking shifts. Stage 4 still leads: ridge and scree up to Pointe des Éboulis, where the exposure comes from altitude and open terrain rather than any climbing move. Next come the Spasimata slabs and footbridge (stage 2) — short and chain-equipped, but genuinely slippery when wet. The ridges and notches of the north — including the Brèche de Capitello at around 2,225 m, on a stage 7 that is otherwise dry with no water — concentrate a few airy steps between stages 4 and 7. As for the alpine variant at Bavella (stage 15), it is optional: the standard route avoids it.
The pack
The rest of the field
The rest of the field sits close together: stages 15, 12, 9, 14, 3, 2 and 8 alternate short days and honest climbs without ever matching the top five. At the back, three stages work as recovery days: stage 5 (just 6.4 km to Ciottulu di i Mori), stage 13 (10.9 km and +266 m, the gentlest by our method) and stage 16, the final -1,053 m descent to Conca. That is where you place the days when your legs ask for mercy.
On the GR20, how hard a stage feels depends more on the day's weather than on its profile — the storm, not the void, remains danger number one.
Advice
Taking on the hard stages
Hard stages are won before you start walking. Leave early: dry rock, cooler climbs, and the high sections behind you before the afternoon storms. Check the weather every day — never commit to a ridge in doubtful conditions. Plan your water, especially on the dry stage 7. And keep the official split on the toughest days: combining two stages into one belongs on the easy sections, never on the top five. The planner recalculates everything at your own pace.