The route starts at Vernas Town Hall. The car park has limited space. If necessary, a large car park is available 200 m away, behind the war memorial, next to Vernas Church.
(S/E) Head north along the D65E (Rue Grande) towards the Chapelle Saint-Joseph.
(1) After passing the Chapel and the Saint-Joseph Fountain, take the path on the right, running parallel to the road. After about thirty metres, take the path on the right, which climbs quite steeply at the start. At the junction, head left down the signposted path leading to the Côtes de Bourcieu. Continue straight along the Chemin du Lac towards Hières-sur-Amby, and further on, follow the shore of Lac d’Hières. You will reach the fork in the path below the Madone.
(2) Take the path on the right towards the archaeological site and keep to the right after 30 metres, climbing up to the Larina plateau. Reach the archaeological site.
(3) Continue to the right to gradually discover La Madone and the cooling towers of the Bugey power station. The cliff overlooks the Rhône plain. Viewpoint from the belvedere. Passing through the remains of ancient dwellings, return to the site entrance, marked by a stone marker bearing the inscription "6".
(3) Take the path on the right, marked in red, to the Fontaine de la Vie, which is the only spring on the plateau.
(4) Immediately turn left down towards the Chemin du Charbonnier. This is a very steep path leading to the Charbonnier quarries, evidence of stone quarrying on the site, particularly slate. Further on, just before reaching the road, there is an information board on the right which is currently (April 2021) illegible, though it is due to be renovated very soon.
(5) Cross the road and continue along the path until you reach a T-junction after about 800 m.
(6) Then turn right onto a wide path to reach the junction where four paths meet.
(7) Take the second path diagonally to the left, which crosses a small Canadian bridge between two rows of barbed wire. This path leads to the orientation table at the highest point of this walk. Facing south, on a clear day you can see Mont Pilat and the Alpine range.
(8) Turn back and, after crossing the small cable bridge again, continue along the route, keeping the tarmac roads on your right and taking the small path in front of you which climbs into the woods.
(9) At Mollard de Bourcieu, turn left towards Vernas. After about 200 m, follow the path on the left and keep to it, going straight on as it descends gradually. Join the Chemin de la Serra, a very wide, roughly gravelled track, which descends to the Fontaine Saint-Joseph.
(10) Turn right, follow it for just 100 m, then turn left towards Vernas. This path does not appear on the IGN map but is clearly signposted. After a short initial climb, turn right to begin the final descent and return to your starting point at Vernas Town Hall (S/E).