The start and finish of this hike are on the SS27, approximately 1.2 km from the Col du Grand Saint-Bernard, on the Italian side. Car park opposite the Alpeggio lo Baou (cheese shop).
Trail marking: Sentiero n°13a
(S/E) From the car park, cross the road and head towards the Alpeggio lo Baou. You will soon come to trail no. 13a, which branches off to the right. Begin the ascent alongside a stream and, after a short flat section, reach a fork.
(1) Take path no. 13a on the right towards the Fenêtre de Ferret (2,698 m). This pass marks the border between Italy and Switzerland.
(2) Climb towards the first rocks in the direction of the Tête de Fenêtre to enjoy a remarkable view of the Col du Grand Saint Bernard.
(3) Return to the pass.
Red and white markings (Switzerland)
(2) Descend the entire Vallon de Ferret and walk alongside the first lake.
(4) Ignore the path on the right, which you will take on the descent, and continue to the end of the last Fenêtre lake.
(5) Retrace your steps to the junction.
(4) Take the path on the left towards Fenêtre d’en Haut or Col de Fonteinte (signposted Col du Grand Saint-Bernard). Gradually approach a third lake and follow the shoreline on your left. After the lake, the path veers off to the left. Begin a long climb up the scree slope. Keep a close eye on the red and white markings, as the route is not always obvious.
Markings: Sentiero no. 13 and 13b
(6) From La Fenêtre d’en Haut, begin the descent towards the Col du Grand Saint-Bernard. Shortly after crossing two streams, you will reach a junction.
Yellow markings, then off-trail
(7) Leave trail no. 13 and turn right onto a path marked in yellow. At around 2,450 m, leave the path and descend off-trail towards the SS27 road to reach a small car park. Cross the road and rejoin the Trail Verbier Saint-Bernard path. Follow this path below the road back to the car park (S/E).