Departure from the car park at the port of Lavau sur Loire.
(S/E) From the car park, turn right, heading south-west.
(1) Turn onto thefirst path on the left and follow it to the observatory. About 200 metres before the observatory, there is a pontoon where you can observe the marshes.
(2) Feel free to climb up. There is a superb view of the marshes and the Loire River from the top of the observatory. Retrace your steps for a few dozen metres, then take the path on your left. Follow it and turn left at the first intersection towards the Étangs du Trou Bleu.
(3) Go around the ponds on the left, then cross the road towards the hamlet of Le Legas. At the entrance to the hamlet, take the path on your left. Ignore the paths on the right or left and continue to La Pélarderie and a T-junction.
(4) Take the road on the left for about 300 metres towards Les Noëls, then turn right onto the path. At the end of the path, turn left towards Le Vigneau, then continue straight on for 500 metres. Turn right towards La Bergerie.
(5) Cross the D3 road and take the Chemin de l'Orme for 300 metres. Take the path on your left.
After a few hundred metres, ignore the path that branches off to the left and continue straight ahead for about 200 metres. You will enter the Marais du Fresnier.
(6) Turn slightly left and take the path that goes straight ahead for 1.5 km towards the east. At the end of the path, turn right and join the road at a T-junction.
(7) Take the road on the left towards Les Coudelières. After a few hundred metres, you will come to a path. Take it on the right for a few dozen metres to reach the Sentier du Syl au Trou Bleu.
(8) Turn right. You will soon reach the road. Follow it to the left until you reach La Close. Continue right on the D90 until you reach the crossroads with a farm building on your left at a place called La Noë Chénier.
(9) Leave the D90 on the left and turn onto the dirt track. Follow this to the hamlet of Le Pavillon, then rejoin the D90.
(10) Turn left, then immediately left onto Chemin de la Goupillais. A few hundred metres further on, cross the bridge over the Étier du Syl, turn right to follow its bank straight ahead and return to the car park at the port of Laveau (S/E).