Departure: 39 rue de l'Église in Saint-Cyr-sous-Dourdan.
The route is marked with blue and white markers.
(S). Take the path south (wash house on your right) to cross the two branches of the Rémarde.
(1) At Pont de Rué, take the D27 to the left for 100 metres, then turn right onto a path at the corner of a house. This path leads to Dourdan, following theGR®111(red and white markings).
(2) At the intersection, with a footbridge without a railing on the right, turn left and walk along a large field. Enter the forest, ignoring a perpendicular path.
(3) At a fork, turn right to stay on the edge of the forest.
(4) Walk past the Vaubesnard farm and rejoin a tarmac road. Follow this road, which turns right and joins the D838 road.
(5) Cross the road carefully and continue on the GR®.
(6) At the entrance to Bois des Brosses, turn left to descend towards Dourdan. Go straight down to Rue Pierre Semard, which you should follow for a few metres to the right, then take the passageway to cross the railway tracks. Turn left and then immediately right into Avenue Amédée Guénée. Then turn left into Rue du Faubourg de Chartres.
(7) Reach the imposing medieval castle and walk around it, passing in front of the market square with its superb covered market. Take Rue Haute Foulerie, then Rue Basse Foulerie, before joining Rue du Moulin du Roi (on the right). Walk back and forth (200 metres in total) along Rue du Puits des Champs to see Maison Yvon (plaque), where Péguy stayed.
(8) Return to the previous crossroads and turn left onto Rue du Moulin du Roi, which leads to L'Orge.
(9) Follow the road for 500 metres until you reach the D386.
(10) Take this road on the right towards the "ring road" for about 80 metres.
(11) Cross and turn left in front of the hospital.
The picturesque road leads to the departmental road at the entrance to Sainte-Mesme after 3.5 km (view of a beautiful manor house on the right).
(12) Turn left onto this road and leave it at the bend to pass under the railway bridge.
(13) Take the path on the right 100 metres further up. Follow the course of the Orge river at a distance, with bends. Go around a pond and come out onto a road at a place called Le Gué de l'Orge.
(14) Take the small road on the left, then continue along a path that climbs gently through the woods and then along the edge of meadows. Descend slightly, cross the river and come out onto the main street of Saint-Martin-de-Bréthencourt. Follow this street (D116) to the left for about 300 metres.
::15 After the railway bridge, don't miss the Chemin des Sources de l'Orge on the right. 250 metres after the cemetery, the path bends to the right.
(16) Take the path on the left, which crosses a stream 50 metres further on. Go up opposite to reach the top of Bréthencourt via Impasse de Marly. Turn left and go around the wash house on the right.
Take Rue de la Croix de Pierre on the right until you cross the motorway and then the railway line.
(17) After 50 metres, turn right onto a path and follow it until it joins a road. Turn right to join the D168.
(18) Follow this road to the right for 300 metres. At elevation 155, turn left towards Long Orme. The landscape is very typical of the Beauce region, with a view of Ablis church on your left. Cross the hamlet (arrow on the right) or ignore it on the left (no arrow) and continue along the small road, ignoring the road coming from the right, towards Guéherville.
In Guéherville, turn left to rejoin the Chartres-Massy railway line that we left before Limours.
(19) Follow this track on the left for about 3km to reach Ablis.
Enter Ablis via Rue des Loges, then turn left onto Rue du Vieux Chemin de Paris. Turn right onto Rue Pierre Trouvé, then left onto Rue du Heaume to reach Ablis Church. On the east exterior wall of the building is a plaque in memory of Péguy (E).
This is the end point of the section.