Petit Bisse and the old Bisse de la Tsandra in Conthey

Wanderweg entlang der Suone, oder auch Bisse genannt (historischer Bewässerungskanal)

Les Coteaux du Soleil

Charming walk along two historical irrigation channels. The second, with info panels, offers a fascinating insight into this ancient Valais tradition. Glorious views throughout.




11.84 km


3:23 h


The “bisses” of Valais are historical irrigation channels built to carry precious water from the glaciers to the fields, orchards and vineyards. At the beginning of the 20th century, Valais boasted about 200 bisses totalling 1,800 km, all built laboriously by hand. In recent years, many have been restored carefully. 

This walk follows the course of two bisses, built in the 15th century to carry water to the fields above Conthey. Both are fed by meltwater from the Tsanfleuron Glacier on the massif of Les Diablerets. Each has its own character and reveals glorious views.

The walk begins at the start of the first channel, the Petit Bisse, where it is fed by the river of La Morge. The bisse still carries water every summer, from early June to the end of October. The delightful path follows alongside, through forest and pastures, as far as a micro-hydro power station at Mayens-de-My – where the water flows into the Bisse de la Tsandra.

The water of this second bisse no longer flows at the surface but through a sequence of underground pipes. A theme trail follows its route, with 24 information panels that explore the history of the bisses, describe the natural habitats along the way and reveal secrets of local wildlife. Along two particularly picturesque stretches, the water flows in the open.

The path is easy, with the gentlest of downhill slopes all the way – apart from one short section where the trail drops from the first bisse to the second. The views, too, are glorious the length of the trail: at first of the wild gorge of La Morge, and later over the vast sweep of the Rhône valley, across its orchards and vineyards to the snow-capped peaks beyond.



  • Delightful gently sloping trail through forest and across meadows
  • Petit Bisse – working irrigation channel, flowing with water during the summer
  • Bisse de la Tsandra – theme trail exploring the bisses, their history and local wildlife

Turn-by-turn directions

The hike starts at the beginning of the Petit Bisse at Grand-Zour, where the road up to the Sanetsch Pass crosses the river of La Morge. A restaurant offers the chance for refreshments before the hike.

The trail follows the full length of the Petit Bisse to Mayens-de-My. Here it turns sharp left and heads straight downhill for 67 vertical metres to meet the course of the Bisse de la Tsandra. The hike then follows the course of the underground bisse, via the theme trail, all the way to Aven. 

Hikers who have arrived by car will need to return to their parking place at Grand-Zour. One attractive option is to start the hike as described, following the Petit Bisse to Mayens-de-My. Then, instead of heading down to Aven, walk up the Bisse de la Tsandra in the opposite direction – effectively following the first part of the theme trail in reverse. This leads all the way back to the river La Morge, a short way downstream from Grand-Zour.


Grand-Zour (1440m)


Aven (932m)

Author's recommendation

After finishing the walk, order a glass of wine made from grapes grown in the vineyards above Conthey: you’ll appreciate it all the more!

Technical information












Best time of the year

  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec


  • Linear route
  • Scenic
  • Geological highlights
  • Fauna
  • Refreshment stops available
  • Family-friendly
  • Cultural/historical interest
Getting there

Public transport

Train to Sion, then postal bus to Grand-Zour. Buses run only in summer: daily from late-June to mid-August, then weekends until early October. At end of walk, postal bus from Aven to Sion (buses run daily, year-round). Find full timetable information at sbb.ch.  


A9 motorway, exit 25 (Conthey). Follow signs for Conthey, Daillon and Sanetsch. Hikers who park at Grand-Zour will have to walk back to their car, as there are no viable connections from Aven back to Grand-Zour by public transport.


At Grand-Zour, next to the restaurant


We recommend: 

  • good footwear
  • clothing suitable for the weather: always carry a waterproof jacket
  • hat or cap
  • sunscreen
  • bottle for water
  • picnic
  • camera
  • binoculars (optional)
  • hiking poles (optional)
  • printout of this hike (click “Print” icon, to download) 

For certain walks:

  • Swimwear

Safety information

Use of the trails and the information on this website is at hikers’ own risk. Local conditions may entail changes to routes. Valais/Wallis Promotion accepts no liability for the accuracy and completeness of information on this website.


For all hikes:

  • Bring a map. Download full description of this route including large-scale map by clicking on “Print” icon, top right of this page.
  • Use marked trails only, and observe all signposting – for your own safety, to safeguard grazing animals and to avoid disturbing wildlife.
  • Close gates after passing through.
  • Please be considerate to other trail users, and to the plants and animals.
  • Do not leave any waste in nature. 

For mountain hikes:

  • Take extra care protecting yourself from the sun at altitude. UV radiation can be exceptionally strong, even in cloudy weather.
  • Plan hike carefully: take into consideration fitness level of each participant, weather forecast and season.
  • Weather conditions can change quickly in the mountains, without warning. Appropriate clothing is therefore essential, along with adequate supplies of food and water. In uncertain weather, turn back in good time. 

For high-altitude hikes:

  • Inform others of the route you plan to take. Whenever possible, avoid going alone.
  • Do not venture onto glaciers without a mountain guide.
  • Take note of the warning signs that point out the constant danger in river beds and along watercourses below dams and reservoirs: water levels may rise rapidly without warning.

Additional information

More information about the destinations: 


Download an illustrated leaflet (in French) on the Bisse de la Tsandra


SwissTopo maps 1:25’000: 1286 St-Léonard and 1306 Sion


This activity is brought to you by Valais/Wallis Promotion