4 - 5
FATMAP difficulty grade
From the Catholic church in the centre of Courmayeur follow the Strada del Villair road north-northeast for 1 kilometre to the Stella Alpina hotel.
At this stage the road continues in the same direction but is called the Rue Val Sapin from here onwards.
Keep following it for a further 600 metres as it climbs to a bridge and a parking area and becomes a gravel jeep track.
Follow the jeep track as it continues to climb.
After 600 metres a large path, signposted for the Rifugio Bertone (1991 metres), branches off left.
Take this and make the long, sweaty climb up to the Rifugio Bertone.
The climb takes 1.5 hours and is hard going but the situation and warm welcome of the Rifugio are worth the effort.
Once suitably refreshed, continue northeast up and onto the Monte de la Saxe ridge.
It takes 40 minutes to reach the ridge crest and an hour to follow it.
The hour on the ridge is one of the highlights of the whole Tour du Mont Blanc; there are perfect views of the Grandes Jorasses, Dent du Géant and Mont Blanc's Peuterey ridge - the longest ridge in the Alps.
From the summit of the ridge (2348 metres), drop down northeast towards the tiny farming settlement of Armina.
Pass just underneath the Rifugio Bonatti and continue descending to the village of Lavachey (1642 metres).