The Orge Valley between the source and Dourdan

Depart from the Sentier du Grillon car park on the road from Sainte-Mesme to Corbreuse, halfway between the two villages, at the crossroads with the Chemin de la Queue d'Auneau. If your satnav does not accept GPS coordinates, programme Ste Mesme, route de Corbreuse, then head towards Corbreuse. The car park is about 1.4 km on the left after passing under the railway tunnel.

(S/E) From the car park, take Chemin de la Queue d'Auneau eastwards (to the left when coming from Sainte-Mesme). At the first crossroads (Le Grillon), follow the yellow^PR® on the right, onto Chemin des Sept Buttes. Towards the bottom of the descent, near the Poulet stream, follow the^PR® on the left until you reach the^GR®111(white and red markings) coming from the right.

(1) Follow the^GR® opposite. After about 400m, it turns left to climb back up to the plateau.

(2) At a T-junction, follow the Route de l'Élu to the right, still on the GR^®. Then take the first path on the left and rejoin the Chemin de la Queue d'Auneau at the Belette crossroads.
Please note that changes in direction are poorly signposted, so you need to look carefully for the markings at crossroads.
Cross Chemin de la Queue d'Auneau and follow the^GR® to the next crossroads with Chemin du Potelet.

(3) Stay on the^GR® which branches off to the right onto Chemin du Potelet and follow it to the roundabout at the entrance to Dourdan. Go around the roundabout on the right to find Rue Lebrun coming from the east (right). Cross the street opposite the gendarmerie, then go around it on the right, taking the passage between the gendarmerie and the houses.

(4) Behind the police station building, follow the Passage de la Gironde at a 45° angle to the right. At the end, cross the Place de l'Étang du Roi, then follow the Chemin de Plaisance at a 45° angle to the left between the houses on the left and the playground on the right. Cross the first path, then follow the path that turns right under the streetlights, on a sort of dyke. Cross a branch of the Orge river and you will immediately come to a crossroads.

(5) Turn right and follow the river to Rue de l'Étang. Follow this road to the left until you reach the crossroads with Rue du Moulin du Roy and the remains of the fortifications.

(6) Follow Rue du Moulin du Roy to the right until you reach the end. Turn right onto Rue de la Basse Foulerie until you reach the Orge. Cross it and turn left onto Promenade René Veneau, which follows the river. Follow the promenade to the end and Rue Saint-Jacques.

(7) Turn left onto Rue Saint-Jacques and, at the roundabout, turn right onto Rue du Chariot along the Orge. At the next crossroads, turn sharply left onto Avenue d'Étampes. Take the first right, Rue du Grèbe Huppé, then immediately left onto Allée de la Roselière. Follow the pedestrian crossing that runs alongside the old fortifications. At the top, join Rue Raymond Laubier and follow it to the right until you reach the last building on the left (on stilts).

(8) Just after the building, turn left onto the stairs leading up to Faubourg Grouteau Park. Follow the path straight ahead until you reach the end of Allée du Parc, which is usually marked by cars parked at the foot of the buildings. Turn left onto the main path that leads to the town hall in Château du Parterre.

(9) Go around the large building on the left and take the access road: Square Great Dunmow. Then continue along Rue Saint-Pierre. At No. 1, on the right, enter the Hôtel-Dieu, which has become a hospital and retirement home. Exit to arrive at Les Halles and Place du Général de Gaulle, with the Saint-Germain d'Auxerre church on your left.

(10) Continue across the square to enter the fortified castle (if open).

(11) Exit the castle and turn left to walk around it in an anti-clockwise direction. At the foot of the keep, continue along the passageway (1.8 m wide) that runs alongside the castle. At the end, take the stairs down to Rue de la Geôle. Continue straight ahead until you reach the crossroads with Ruelle de l'Abreuvoir.

(12) Take the alley on the right to the middle, then the narrow passage on the left. It turns and then descends to the left to rejoin Rue du Moulin du Roy. Follow it to the right to rejoin Rue de l'Étang.

(6) Move to the right and use the pedestrian crossing to cross the boulevard. Follow the path opposite that runs alongside the Orge. A little further on, you will find the path leading into the town at the start and the^GR® coming from the right on your left. Continue straight ahead along the Orge. At the end, turn right and follow the path and the^GR® for about 50 metres along Rue du Potelet until you reach the next crossroads.

(13) Turn left onto Rue du Mesnil, which runs alongside a park (Yellow^PR® ). When you reach the entrance gate to the Château du Mesnil estate, leave the Yellow^PR® and take Chemin du Mesnil on the left. Pass the estate (castle on the right) and continue until you reach a path coming from the left with a wooden barrier.

(14) Take the path on the left and cross a branch of the Orge river. Continue to the right between the two branches of the Orge. Pass Moulin Grillon (still in operation, on the left) and continue until you reach a gate where the path ends. Turn right to rejoin the^PR® path and follow it to the left. After about 100 metres, take the path on the left to walk along the Fontaines Bouillantes ponds. Walk around the first pond clockwise to pass between it and the small pond that follows. Turn left to walk along it and arrive at the large pond with its benches and tables.

(15) Walk along the north side of the large pond to the north-west end (wooden sign for the fishing company). Leave the pond on the right at the sign and rejoin Chemin du Milieu to pass under the railway line on the left and continue straight ahead towards the west (do not turn right). Reach the entrance to Petit Sainte-Mesme and continue west along Rue Julien Minos, leaving the signpost for Montée du Garde on your right.

Continue to Route de Dourdan (D116) and turn right towards the centre of Sainte-Mesme. After the left-hand bend, in front of the castle entrance gate, pass the town hall (on your right) and continue to Route de Ponthévrard, which leads to the church.

(16) Do not go towards the church, but cross to the left to find the Sainte-Mesme spring and fountain.
Go back and turn left onto Rue Charles Legaigneur until you reach the next crossroads. Turn left onto Chemin du Moulin de Corpeau. Go under the railway line and take the path on the left. At the end, follow the path on the right into the woods until you find the path and the yellow^PR ®.

(17) Take the path on the right and follow the yellow^PR® along the Orge until you reach the tennis courts, then the Vieux Murs pond on the other side of the fence.

(18) Continue around the pond and follow the path to the small road of Gué de l'Orge, turning left. Pass in front of the Gué de l'Orge estate and continue to the entrance of Saint-Martin de Bréthencourt via the Grande Rue, turning left. In the middle of the village, after the town hall, turn left towards the church.

(19) In front of the church, turn right onto the steps leading to the car park, then left onto Route de Corbreuse. Pass the tennis courts. Continue along the road, which turns left uphill. After passing the woods, the road turns right in front of the Brandelles farm. Follow it along the apple trees until you cross Chemin de la Queue d'Auneau at the end of the wooded area.

(20) Take the path on the left. Ignore a path on the right and walk along the edge of the woods. Further on, at a fork, take the path on the right (opposite) and enter the woods. Continue to the car park where you started (S/E).

Picnics are possible at the Fontaines Bouillantes ponds, especially at the third pond, which is the largest.
Avoid hiking during rainy periods as some sections can become marshy.
Allow 7 to 8 hours, including a visit to the town and time for lunch.

(E) First, we cross the Ouye forest, which was part of the Dourdan forest. The name comes from the verb Ouïr (hear). (Hear ye, hear ye, good people). Legend has it that a prince, the future King Louis VII the Pious (1120-1180 - great-great-grandson of Hugues Capet), got lost in this forest near the Royal Castle of Dourdan. Seeing nightfall approaching, which was very frightening for the inhabitants at a time when wolves roamed the area, he called for help and was heard by his companions who were searching for him. In gratitude, he had the Abbey of Ouye built on the site, which had access to the surrounding woods. It should be noted that he was not destined to become king, but to enter the priesthood. Louis VII's son, Philip Augustus, confirmed the decision and the rights of the abbey.
Today, the abbey is a reception centre for the Diocese of Paris, accommodating groups of 10 to 100 people.

(6) At the crossroads: remains of the surrounding wall that was built in the 15th century to protect the town following the kingdom's many wars. We will find them again after the point (7), on the other side of the Orge.

(9) Town hall: The name Dourdan comes from "dour", meaning water, and "dan", meaning hill, in Celtic.
In 1725, Michel Jacques Lévy, advisor to the king and bailiff of Dourdan, had the Château du Parterre built. In 1809, his heirs sold it to the town, which became the sole owner of the château in 1863.
Hôtel Dieu – 1, rue St Pierre: In the 13th century, the Hôtel Dieu de Dourdan was built at the same time as the château and the church of Saint-Germain. Like them, it was founded by the royal family. It is located in the heart of the town, in accordance with the rules in force at the time. Its mission was to welcome weary travellers, pilgrims on their way to Compostela, the elderly and the town's destitute orphans.

(10) Market hall and church: the market hall is of medieval origin, but was rebuilt in 1836 on the foundations of the medieval market hall. See the sign at the entrance.
The Church of Saint-Germain d'Auxerre (or l'Auxerrois) was begun in 1150, and therefore built before the castle, but was remodelled several times following damage during various wars. Use the main entrance on the left, facing the castle.

(11) The Castle: Castle - Dourdan, capital of the Hurepoix region, halfway between Paris and Chartres, was important to the Franks from the 6th century onwards, after the conquest of Clovis.
The medieval period established Dourdan as a royal town. Hugues le Grand, Duke of France, died in Dourdan in 956. His son Hugues Capet was born here and became King of France, and the town became the property of the Crown. In 1220, to defend the cradle of the Capetians against the powerful local barons of Monthléry, Châteaufort and Chevreuse, Philippe Auguste chose to erect a powerful stone fortress in the heart of the town. A remarkable example of military architecture, built on the model of the Louvre, this castle is one of the only buildings in Île-de-France to have retained most of its defensive structures: dry moats, curtain walls, towers and entrance gatehouse. A drawbridge and portcullis once ensured its defence. Arrow slits pierced into the sides of the towers are still visible. However, following the Hundred Years' War and the Wars of Religion, the interior buildings and upper parts of the castle were destroyed. Only about one-third of its original height remains.
The keep, symbol of royal power, is circular in shape. Isolated by its own moat, it had two drawbridges, ensuring autonomous defence. About forty metres high, the main tower served as a watchtower. Its upper part once included hoardings and a pepperpot roof.
In the 14th century, the castle, a royal domain of the Capetians, was given as an appanage to Louis d'Évreux, brother of King Philip the Fair. In 1314, following the Tour de Nesle scandal, his niece Jeanne de Bourgogne was imprisoned in the keep for a year while her trial was underway. Found innocent, Jeanne later became Queen of France. From 1430 to 1433, a comrade-in-arms of Joan of Arc, Étienne de Vignolles, known as La Hire, was also held captive in the keep.
It was subsequently converted into a prison and housed prisoners until 1852. The castle became private property. One of its owners, Joseph Guyot (1836-1924), a scholar and historian, spent his life restoring it.

(14) After the Château du Mesnil, along the Orge river: the Grillon mill on the other side of the Orge is still in operation and sells flour. In this video, you can see a film about the mill and how the enormous machinery works, using the famous millstones from La Ferté sous Jouarre.
The gate is that of the old access road to the Château de la Garenne, on the other side of the Orge and the D116.

(15) The Fontaines Bouillantes ponds are wetlands that are home to a multitude of bird and insect species. They are also home to flora that thrives in this type of environment. The poplar grove is home to a colony of broad-leaved helleborine, a species of orchid that is relatively common in our region.
These ponds provide lodge and food for many species. Indeed, as a favourable environment for birds, it is easy to spot mallards, coots and other species such as kingfishers and grey wagtails.

(16) Sainte Mesme: In the 5th century, Sainte-Mesme was the daughter of the Frankish king Dordanus. One of the servants in Dordanus's household introduced her to the Christian religion without her family knowing. Furious to learn that his daughter had renounced the pagan gods, he asked his son Mesmin to behead his sister to save the family's honour. Mesmin buried his sister's head in the spot where a miraculous spring gushed forth. Its water cures fevers.

(19) Saint-Martin de Bréthancourt: village where the Orge spring is located. Getting there involves a 2km detour for the round trip. Not much is visible as it is collected in a building.