- Ascent: 500 meter
- Descent: 900
- Time: 5hr
This day feels like a day off, with two alternatives. There is a high level ridge walk to Refuge de l’Onda or a low level valley walk. The low level alternative is actually the main GR20. This variant sees no scrambling and has mostly gentle gradients all the way to Refuge de l’Onda. The high level alternative is a more direct route and even though there is some scrambling involved, it is actually half an hour quicker because there is significantly less height lost at the beginning of the stage. The route described below is the low level, main GR20.
The day starts with a steep descent down the valley alongside the Ruisseau de Manganellu. On a hot day there are many tempting swimming holes to go for a dive. Luckily the steep gradient soon eases. The GR20 follows the river all the way down to the popular Bergeries de Tolla where you can buy fresh bread and Corsican cured meat and cheese.
From Bergeries de Tolla there is still a 500 meter climb all the way up to Refuge de l’Onda along the Ruisseau de Mazzola. Along the way you’ll ford numerous streams. Note that these streams become uncrossable in severe weather so beware of thunderstorms! When worst comes to worst, you can always bail down the valley by following the Ruisseau de Manganellu all the way till you reach the road. From there you can hitchhike to Vizzavona. The climb up to Refuge de l’Onda is long but with gentle gradients along a 4×4 path.
Refuge de l’Onda is beautifully located on a huge green pasture. To avoid confrontation with the cattle you can pitch your tent in a fenced off part. The Refuge runs a basic shop.