Stage 8: Petra Piana → Onda

9 km from Refuge de Petra Piana (1842 m) to Refuge de l'Onda (1430 m), with 220 m of ascent and 630 m of descent.

Walking time by fitness profile

Times computed with the RandoNav planning algorithm. Breaks not included.

On the trail

A day of two personalities. From Petra Piana the standard route drops southwest into the Manganellu valley, and the trail turns positively Mediterranean: shady pine forest, granite slabs polished by the river, and a string of natural swimming pools that will test your schedule discipline. The Bergerie de Tolla, roughly halfway at 1,034 m, sells cheese, saucisson and cold drinks — one of the great mid-stage stops of the GR20, and nobody walks past it without at least slowing down.

The alternative is the ridge variant along the crest via Monte d'Oro's shoulder — spectacular and exposed, for steady weather and steady legs only. Either way the day finishes with a climb back up to Refuge de l'Onda at 1,430 m, set among grazing sheep and pigs on an open saddle, its bivouac area fenced like a small stockade — you'll see why when the pigs start patrolling at dinner time. With only 220 m of total ascent on the valley route, this is the closest the northern GR20 comes to a rest day. Swim, eat cheese, dry your socks.

Start / end

Stops along the way

These places between the endpoints let you split the stage into shorter days:

About this stage

Stage 8 links Refuge de Petra Piana (1842 m) with Refuge de l'Onda (1430 m) over 9 km, climbing 220 m and descending 630 m. This stage lies in the northern half of the GR20 (before Vizzavona), the rockier and more technical part of the trail. One stop punctuates the route, so you can split this stage into shorter days. Water is available at every stop on this stage. Along the way only snacks and meals are available — no full resupply until the end of the stage.