Nanchez Peat Bog trail
Nature trail
Nanchez Peat Bog trail

Nanchez Peat Bog trail

Fauna – Flora
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A hollow carved into the centre of a hill, the Combe de Nanchez landscape is the result of a long human and natural history. Head out along the winding boardwalk, immerse yourself in the atmosphere and unearth some of the Nanchez peat bog's secrets.
Wooded ridges covered with fir trees and spruces, houses scattered across hamlets, surrounded by pastures and hay fields, wetlands and peat bogs nestling at the bottom of the combe all shape this distinctive landscape.

9 points of interest

  • History & Heritage

    The evolution of life and buildings

    The rural house was first the one belonging to the farmer and livestock breed, where men and animals lived together. As from the 18th century, cheese specialisation and the pooling of milk in cooperative structures - “fruitières” - brought farmers out of a self-subsistence economy. In terms of buildings, the farm became bigger: a storey is added to include bedrooms, a second stable is sometimes built to accommodate more animals.

  • Natural environments

    The Nanchez peat bog

    Peat bogs are characterised by a surface that is constantly water-logged, where peat forms and accumulates: it is a type of bedding made-up of dead vegetation which has badly decomposed due to the absence of oxygen. Life conditions are demanding in these environments and this means that the species that live here must adapt to the omnipresence of water, to a relatively cold climate and to the chemical composition of the soil.

  • Flora


    This small carnivorous plant traps insects using its sticky digestive-juice covered hair. This adjustment allows the plant to acquire additional nutrients in this environment where its roots struggle to find enough food.

  • Flora

    The bog bilberry

    This phony blueberry favours environments that are slightly acidic, which is why it can be found in raised bogs or bogs that are in the process of drying out. Its edible berries, which mature mid-summer, are not as sweet as blueberries.

  • Flora


    This plant’s roots produce toxic secretions which hinder the growth of other species. It is often called common heather.

  • Fauna

    The violet copper

    This butterfly is typical of northern regions. Adults can be seen flying around in May and at the beginning of June. Females lay their eggs by sliding backwards under the leaves of the common bistort. Caterpillars then complete their development on the underside of these leaves.

  • Flora


    Their silky tuft does not appear during the flowering stage but rather the fruit stage: the cotton-like fibres that make-up this tuft are carried by the wind to aid the dispersal of its seeds.

  • Flora

    Mountain pine

    In the Jura, these trees are found almost exclusively in peat bogs: its bushy silhouette, its short needles that grow in pairs of two and the hook on the leaves of its cones are some of its distinctive features that will help you to identify one.

  • Viewpoint

    Belvedere over the Fort

    Already on the map in 1835 under the name “La Roche du Fort”, this belvedere – cleared only a few years ago - opens onto the Anchey combe (Prénovel-Les-Piards), the Nanchez forebay and the peat bog. To the south-east you can see the High-Jura mountain range from the Dole to the Reculet.

    At the foot of the belvedere are several funnels, one of which is very visible near the road, and which create overflows during floods. When the sawmills downstream were in operation, the factory workers would try to block them in an attempt to keep enough water for their hydraulic wheels. Regardless of the flow rate, the forebay runs into the karst behind the hamlet of Chaux-des-Prés. Its springs up again 27 km further along, in the Bienne valley.


To the front of the PRENOVEL church, the route heads off to the right (yellow waymarking) via the D 232, then quickly (70 m), take the road descending to your right, bordered by a few houses, until you reach La Vigne. Continue on a good white path until you reach Le pont des Janiers bridge. The path crosses the Nanchez to your right and ascends towards the Cotat Bossu.

Following this grassy ridge, the path leads to THE PEAT BOG. Embark to your right along the winding boardwalk, immerse yourself in the atmosphere and unearth some of the Nanchez peat bog's secrets by reading the markers found along the trail.

At La Croisée des Biefs, continue in the same direction, cross a new walkway near where the Nanchez meets the Trémontagne creek and come to a road at Le Pontet.

Follow the road to the right for 150m and ascend to your left to the Belvedere which overlooks the combe.

Go back to Pontet and la Croisée des Biefs the same way.

Take the path to your right and cross the Nanchez again. From the Walkway, follow the path to the left and reach the pont des Janiers bridge then, going back the same way you came, return to PRENOVEL.

  • Departure : Prénovel village square
  • Arrival : Prénovel village square
  • Towns crossed : Nanchez and Grande-Riviere Chateau


Sensitive areas

Along your trek, you will go through sensitive areas related to the presence of a specific species or environment. In these areas, an appropriate behaviour allows to contribute to their preservation. For detailed information, specific forms are accessible for each area.
Impacted practices:
Aerial, Aquatic, Amenities, , Underground, Land-based
Sensitivity periods:
Conservateur : Laurane Parc Naturel Régional du Haut-Jura29 le village39310 LAJOUX03 84 34 12 30


This trail passes through pastures with livestock. To respect the owners and farmers granting you passage, and for the security of livestock and wild fauna, we ask that you remain on the waymarked paths. Use the adapted passageways to get across fencing and be sure to close gateways behind you.

Please keep your dog on a lead if you have one.

Wild flowers are beautiful in the peat bog and in the surrounding fields, they may be rare and protected and often wilt quickly. Do not pick them! They will delight the next hikers.

In case of forest works (felling, skidding, etc.), for your safety, know when to stop and turn around.

In the adapted area of the peat bog (boardwalk), between THE PEAT BOG and Le Pontet, for the safety of all and to respect this unique environment, there are a few additional rules:

  • Do not leave the boardwalk
  • Cycling is not authorised

Information desks

Tourist information centre - Haut-Jura Grandvaux

7 place Simone Veil, 39150 Saint-Laurent-en-Grandvaux (0)3 84 60 15 25


To visit and get about in the High-Jura, visit, the eco-mobility portal listing all means of transport within the Park.

Access and parking

15km from Saint-Laurent-en-Grandvaux, via the D 678, the D 146 followed by the D 28 and the D 232.

Parking :

In the village's centre, near the Community Hall

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