Stroll along an irrigation canal built into a cliff | Add a side trip to Lac de Tseuzier
Easy return bisse du Ro hike (T1) | Harder loop options (T2) | Ski resort nearby
The bisse du Ro is an old irrigation canal near the ski resort of Crans-Montana in the canton of Valais/Wallis.
Most bisses are dug out of the earth or rock — but the bisse du Ro runs along a sheer cliff. It was built by attaching planks to the cliff face and then placing wooden canals on top of the planks. This was a massive feat, considering the bisse was built in the 12th century!
The walk offers great views of the mountains across the valley to Anzère. We combined the bisse du Ro hike with a side trip to Lac de Tseuzier. The lake’s beautiful turquoise waters are even more stunning in autumn when the surrounding larches become golden.
Three walking options are described below:
►Very easy bisse du Ro hike along the canal and back | 9.4 km | 325 m↑↓ | T1
►Easy loop walk along the bisse & back under the cliffs | 10.2 km | 615 m↑↓ | T1–T2
►Medium partial loop hike adding a side trip to Lac de Tseuzier | 18.4 km | 800 m↑↓ | T1–T2
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Practical info
Getting there & away
The hikes described here start and end in Crans-Montana, a large town and ski resort above Sierre in the Swiss Alps of Valais/Wallis. You can drive to Crans-Montana or take a train to Sion then a bus. Lac de Tseuzier is also served by bus from Sion.
►Directions to the trail head (Parking du Bisse du Ro) on Google maps
What to bring
You don’t need any special equipment to do these walks in summer or early autumn, but will need snowshoes or mountaineering equipment if there’s snow on the track. Whatever the season, be prepared for sudden changes in weather — especially if you include the side hike to Lac de Tseuzier. You’ll also be above the treeline on this side hike, so don’t forget sun protection! You can eat at a restaurant in Crans-Montana or Lac de Tseuzier, otherwise take a picnic lunch.
Trail description: Bisse du Ro hike
The walk along the bisse is mostly a stroll through the forest along a mountainside, with plank bridges to traverse the cliff faces. There are some scary pictures online of rickety planks resting on not much, but don’t be put off: this was when the path was under construction. As you can see from our pictures, the bridges are very secure now.
The trails after the bisse are regular hiking trails, and well marked. There is one exposed section just after the bisse, but it’s not too bad in dry conditions.
There are no restaurants or shelters along the way, but there are a few picnic benches and one table along the bisse.
Very easy return walk
Crans-Montana – Bisse du Ro – Crans-Montana
Highest point: 1,662 m
Height gain: approx 325 m
Trail level: T1
Technical details: mostly a very good path or board walk
Distance: 9.4 km
From the trail head at the parking area, follow the walking signs for Lac de Tseuzier. After a short climb up to the bisse the path is more or less flat, and follows the mountainside. You have to duck in a few places as you traverse the cliffs. There are panels along the way explaining the history of the bisse.
After the end of the bisse du Ro you’ll arrive at an exposed part: a 200 m section where it’s forbidden to stop due to the danger of rockfalls. Take the same path back to Crans-Montana.
Easy loop walk
Crans-Montana – Bisse du Ro – under the cliffs – Crans–Montana
Highest point: 1,662 m
Height gain: approx 615 m
Trail level: T1–T2
Technical details: steepish trail in parts; short exposed section with danger of rockfall
Distance: 10.2 km

Walk along the bisse as described above and continue through the exposed part. It sounds scarier than it is. The trail continues along the mountainside to the head of the valley, where there are more picnic tables. Follow the trail with signs to Lac de Tseuzier until the sign for the grande bisse de Lens, where you turn left.
The trail takes you down through the forest and under the cliffs you traversed while following the bisse du Ro. At some point there’s a fork for Crans-Montana or the grande bisse de Lens — follow the left path to Crans. Walking down means, of course, walking back up — this part is a little steep. You end up where you started at the path for the bisse du Ro.
Medium partial loop hike
Include a side trip to Lac de Tseuzier
Highest point: 1,820 m (just above Lac de Tseuzier)
Height gain: approx 800 m
Trail level: T1–T2
Technical details: steepish trail in parts; short exposed section with danger of rockfall
Distance: 18.4 km
From the end of the bisse du Ro, keep following the signs to Lac de Tseuzier. The path is a little steep in places. Once you’ve finished admiring the lake, walk back the same way until the turn off for the grande bisse de Lens on the right — take this turn off to return to Crans-Montana under the cliffs, as described above.
Nearby mountain fun
Eating & sleeping
There are many eating and sleeping options in Crans-Montana.
Other hiking options
If you take the trail under the cliffs, you can walk to Lens instead of Crans-Montana by following the grande bisse de Lens trail. This route is marked with a big sign saying it’s not recommended for people suffering from vertigo. We were immediately tempted to take it, but unfortunately didn’t have enough time. We’ll definitely be back to do it another day!
There are many other trails and mountaineering possibilities around Crans-Montana, Anzère and Lac de Tseuzier — zoom in on the map above and you’ll see them crisscrossing the mountains.
The long-distance 62 “Walliser Sonnenweg” trail to Brig starts in Crans-Montana.
Skiing
Crans-Montana and Anzère are both large ski areas in winter. The Anzère resort is covered by the Magic Pass.
►Crans-Montana ski trail map
►Anzère ski trail map