Leave the Portalet car park and turn left and then right on to Avenue Fabre de Sérignan. At the Bassin roundabout, take the 2nd exit on the right and cross the bridge. At the next two roundabouts, continue straight ahead towards Les Névons, Cours René Char. At the end of this Avenue, take the 2nd exit on the right at the next roundabout and turn right again immediately on to Chemin de Palerme. You are in the Sorgues plain with a view over the Vaucluse Hills. Continue straight ahead and, at the stop sign, continue straight ahead along Chemin de la Lône. You will see the hilltop village of Saumane-de-Vaucluse.
At the junction, turn right and, at the next junction, turn left on to Chemin de Mousquety. Before the junction, turn left on to Chemin de la Coutelière. Continue towards Saumane-de-Vaucluse, cross the river and turn right immediately after the Galas bridge. Then, turn right towards Fontaine-de-Vaucluse, pass beneath the aqueduct and you will arrive on Place de la Colonne. Apart from the famous resurgence, you will also be able to visit the Vallis Clausa paper mill and the many museums in the village.
To return to Isle-sur-la-Sorgue, cross the bridge via the D24, pass beneath the aqueduct. Take the road towards Isle-sur-la-Sorgue, cross the Sorgue again and turn right after the bridge and then left towards Saumane-de-Vaucluse. When you reach the junction, continue right towards Saumane-de-Vaucluse and cross the Carpentras canal. At the next junction, you have two options: either turn left and return to Isle-sur-la-Sorgue along the D175, or turn right and climb up to the hilltop village of Saumane-de-Vaucluse. A 4 km relatively steep climb to this magnificent village at the top of which stands the fortress which used to belong to the family of the infamous Marquis de Sade, from where you can admire the terraces and dry-stone huts. Make your way back down along the same path and take the D175 towards Isle-sur-la-Sorgue. Admire the view over the Luberon and the Alpilles.
At the junction, turn right and then turn left at the roundabout. At the next roundabout, take the 2nd exit on the right and pass the supermarket. Continue straight ahead for 1.5 km to the site of the watershed. To reach Isle-sur-la-Sorgue, take the cycle path which follows the river towards the town centre. You are back at the Bassin roundabout. Take Avenue Fabre de Sérignan and then turn left to the Portalet car park.