The Tour d'Aï is short and powerful. The via ferrata is difficult, highly exposed, at one point even with a slight overhang, and has excellent safety. Even on the normal route there is a ladder and points which are equipped with chains and hand-rails; it is an exposed route which in the upper section is on the side of the mountain in shade.

Difficulty
K4. Difficult.

Starting-point
From Aigle on the Lausanne - Sion rail line with the rack-railway to Leysin, district of Feydey (1,389 m). It is 10 minutes eastwards on foot to the valley station (approx. 1,320 m) of the gondola cable-car to Berneuse (2,045 m); this operates from May to October.

Walk-in
From the Berneuse mountain station, head northwards down into a hollow (1,905 m) with a chairlift valley station. On paths, climb more or less along the lift run up to the grassed ridge. Traverse to the right and over a mound of scree to the start of the via ferrata (approx. 2,190 m) on the west wall, roughly in the fall line of the left of the yellow overhangs.

Tour d'Aï via ferrata
The via ferrata follows the "Voie des Vires" over a series of ledges running diagonally upwards and to the right, climbs up through a chimney, conquers a vertical to overhanging wall, follows a grassed ledge to the left, and leads over an edge to the top of the Tour d'Aï.
 
Descent
The descent uses an exposed, marked normal path over the south-east ridge, firstly bearing left of the cut over steep slopes, then over a sharp ridge of rock which widens out and becomes grassy. Finally, keeping to the left, you reach a rocky channel. At the foot of this, bear right to Chalets d'Aï (1,892 m) above the lake bearing the same name; from here you can climb again in 20 minutes to the Berneuse mountain station, or take hiking paths down to Leysin-Feydey in 1 hour.

Region: The Alps of Vaud, Leysin
Peak: Tour d'Aï (2,330 m)
Time required: climb 2 hours, descent to the Chalets d'Aï 1 hour, further climb to Berneuse 20 minutes, further descent to Leysin-Feydey 1 hour.
Variation in height: climb 430 m, via ferrata 140 m; 1,070 m to Leysin-Feydey.