The route starts in the village of La Berderie.
To get there: from the village of Saint-Mars, head towards Machecoul. After about 5 km, take the road on the left, then continue straight on to park at the far end of the village.
(S/E) Walk up through the village to the Saint-Mars–Machecoul A-road. Cross it carefully and, a few metres further on, you’ll reach a crossroads with a footpath.
(1) Take the path on the left; it is a grassy track. Continue until you reach a T-junction with a stony path.
(2) Turn right onto it towards Les Grandes Vignes, then Les Pains Bénis.
Cross a local road, then at the edge of a wood, turn right. Walk alongside the wood and the hamlet of Bois Joli. You’ll reach the junction with the D64.
(3) Cross this road carefully, then head straight ahead. Reach the edge of another woodland.
(4) Turn right at the edge of the woodland to join the Chemin de la Messe.
Cross a local road. Reach the lower part of the village of La Pohérie. Turn left and you will soon reach the Levée des Platanes.
(5) Here there are two options depending on the season:
- continue straight on towards the Grand-Lieu marshes (this is the route shown on the map); shortly afterwards, you’ll reach the junction with the sandy path,
- if the area is flooded, take the road on the right to walk alongside the flooded marshes.
(6) Take the sandy path on the right. After walking in a straight line, you’ll reach the riverbank. Turn right and, a few metres further on, you’ll find the car park for the village of La Berderie (S/E).