Mont Ussy, Rocher Cassepot and Tour Denecourt

Parking: Park in the small square at the traffic lights between the Route de la Bonne Dame leading to Avon and the D606, on the uphill side as you leave Fontainebleau. The square is opposite the "Chapelle Notre Dame du Bon Secours" chapel, relative to the crossroads.

(S/E) Behind the wooden barrier, look for the two blue trails and take the one that climbs furthest to the left. Before reaching the plateau, the path will veer right at the foot of the "cliffs", i.e. the lines where the quarry workers used to cut the stone, then slip to the left to climb up to the plateau and arrive at the junction of the blue paths, with a sign on a tree and a description on the rocks. Enjoy the view of the valley.

(1) Head north-west and take the blue trail towards the Croix d'Augas (at the start, look for the signs for "Vers Croix d'Augas" on the trees) until you pass a medallion and a plaque in homage to the painter Paul MERWART at the edge of a sunken path (*), then next to the restaurant to arrive at the Croix d'Augas crossroads.

(2) Cross the D606 via the bridge, then turn left onto the blue trail no. 1-3.

(3) Follow circuit no. 1 on the right to join the Route forestière de la Buttes aux Aires. Be careful to follow the markings until you reach the road to find the path opposite. Cross this road and follow the blue markings. Continue along the path through a long winding passage between the rocks until you reach the "Réserve Biologique Intégrale" (biological reserve), which is closed to the public by signs.

(4) Turn right onto the Nid de l'Aigle. Cross the Route Leclerc and the Route de la Reine and head north-northwest until you reach the Route forestière de l'Hippodrome de la Solle (tarmac). Follow this road to the right until you reach the D606.

(5) Cross the D606 (be careful, this is a tricky crossing) and continue straight ahead on Route de la Butte à Guay for about 100 metres. Then turn left onto the blue trail no. 3. Go downhill to join Route Tournante des Points de Vue du Rocher Cassepot, which you follow to the right until you reach the junction with the gravel road of Vallée de la Solle.

(6) Cross the Route de la Vallée de la Solle and continue on the blue trail no. 3. This is the trail on the left (west-northwest) between the path going up and the path going down. Go around Rocher Cassepot clockwise, staying on trail no. 3. Cross the blue trails 4-3 and then 14, keeping to the right on trail no. 3. You will reach the Esplanade viewpoint.

(7) Continue on the Blue trail No. 3 (do not confuse it with the^GR® Blanc/Rouge) until you reach the Route de la Vallée de la Solle again, but further east.

(8) Leave the Blue trail no. 3 on your right and follow the Blue trail no. 3-2 towards the Denecourt Tower. Be careful, the trail is not very visible and the signpost is poorly oriented. Cross the Route de la Vallée de la Solle and immediately turn left onto the Blue trail parallel to and to the right of the road. Continue to the D116. Cross this road and turn left to follow the blue signpost no. 3-2 to the Denecourt Tower. The path is sometimes poorly marked. Follow the main trail. Cross the Jean-Bart forest road (tarmac) and join the path that follows the blue signpost no. 2 coming from the right on the next climb. Follow it on the left to the Denecourt Tower. Follow the blue trail no. 2 to the car park. However, be careful of variations of no. 2, which are used for the return journey or other starting points.

(9) Climb the tower for the view. Leave the tower by taking the first Blue trail on the left as you descend from the tower. This is No. 2 towards Les Fontaines (sign). Be careful! Do not take the misleading shortcut that descends steeply to the left and appears to be marked. Continue horizontally at the foot of the rocks, heading west, until you find a beautiful paved path on the left (south) to descend to the Carrefour de la Tour Denecourt (3 paved roads).

(10) Look for the blue sign for No. 2 on the right, then follow it to the left (south). Pass the Touring Club fountains, Désirée, Dorly, Isabelle and La Roche Éponge. Shortly afterwards, down on the right, you will see the Colinet Cave with a medallion. About 250m after the cave, you will reach a signpost for the Blue trails. Take trail no. 2 on the right and you will come out onto the Route forestière de la Reine Amélie (tarmac).

(11) Cross the Route de la Reine Amélie. Follow the blue signpost no. 2 opposite, which remains parallel to the road until you reach the Croix du Calvaire. Please note: the blue trail sometimes runs close to the tarmac road. Do not take the road, otherwise you will lose the trail, which branches off to the left. You will arrive at the cross.

(12) Take the Route du Calvaire northwards, opposite the cross, for a few metres, then turn left onto the blue trail no. 2. At the end of the "U" pass, at the crossroads of trails no. 2, take the one that descends to the left to reach the car park
(S/E).

The start could have been at the Croix d'Augas. However, the proximity of the restaurant attracts thieves who search cars. In addition, the climb and descent from Notre-Dame de Bon Secours are well worth the effort.

The Denecourt-Colinet trails, marked in blue, are numbered. "2" means blue trail No. 2. "1/2" means a trail shared by Nos. 1 and 2. "1-3" represents a link between trails No. 1 and No. 3. "8-8" represents a shortcut on trail No. 8.
The white/red markings here indicate the^GR® No. 1.

The names given to the rocks and sites date back to Denecourt and Colinet, the foresters who created the trails now marked in blue. These names come from mythology, from well-known figures such as the painters of the forest (Barbizon School) and from the need to reward the donors who financed the creation of the trails... and from the imagination of the foresters.

(S) At the end of the climb, A: Raffet Cave. B: Ravine Cave. C: Camée Cave. D: Ravine viewpoint on the edge of the plateau (viewpoint).

(1) Arriving below the Croix d'Augas inn, the MERWART plaque and medallion. Right next to it was once the Caverne d'Augas. The site is a quarry face and therefore did not exist in the past. The entrance to the cave was just to the left of the medallion.
In 1868, Denecourt described this site as the largest cave in the forest, capable of sheltering 200 people once cleared. The 3-metre-thick monolithic vault guaranteed its solidity. Colinet, Denecourt's successor, had a 45-metre-long visitor circuit dug out with an exit 20 metres from the entrance. Then, with the wars, the cave was forgotten and the sand released by the quarries largely filled it in again. However, after 1945, the site was re-excavated and brought back into fashion, reviving the inn above, which became the Taverne d'Augas. However, as the cave was enlarged, it exceeded the surface area of the vault that guaranteed its solidity, which made it all the more fragile as the ground was shaken by the dynamite work carried out on the N6 road in the 1970s. The road engineers therefore had the entrances filled in with sand.
On the night of 3 March 1986, the owners of the tavern, who were sleeping there because of burglaries, were awakened by an explosion that shook the tavern violently: the cave had collapsed, ruining the restaurant, whose floor had subsided by 80 cm.

(2) B: Vervins Cave. D: Gros Belvedere. E: Bertrand Duguesclin Rock. G: The Lady of Augas. H: Gravine Tunnel. I: Edgard and Marguerite's Shelter. *: Hiding place of the Three Sisters.

(3) Q: Passage of Camille Flammarion. N: Chaos of Corneille. M: Rock of Cid. L: Chaos of Shakespeare. K: Chaos of George Sand. J: Cave of Maria Brunetti. H: Room of Lucrezia Borgia. G: Oasis of Marion Delorme. F: Chaos by Victor Hugo. E: Passage by Armand Cassagne. D: Chaos du Tasse. B: Rampart of Mont Ussy. A: Rock of Casanova. Z: Rock of Fontanges. V: Tunnel of Himely.

(4) On the forest road of La Solle, views of the La Solle racecourse.

(6) U: Meissonnier's workshop. -: Portico by Francisque Sarcey. T: Arcade by J.J. Weiss. S: Roche Paul Domet. *: Arch by Crozette Desnoyers. P: Grotte de la Pucelle. O: Défilé de Vaucouleurs. N: Point de Vue de la Solle. M: Chaos by Émile Augier. L: Parade by Gounod. K: Belvédère du Sport. J: Rampart of Rocher Cassepot. I: Roche du Vautour. H: Belvédère des 3 Frères. G: Corniche du Cassepot.

(7) F: Point de Vue de l'Esplanade. Returning to the plateau, beautiful lines of quarry cuts. Les Mares Froideau. E: Rocher de la Cinquantaine. D: Roche Céleste. C: Roche Caroline Dussaut. B: Belvédère Carnot.

(8) After the D 116, D: Rocher Charles Garnier. -: Passage des Farfadets. *: Miroir Magique. C: Roche Gaffory. B: Abri de Suzanne.
After rejoining the GR: G: Abri Louise. H: Grotte Adam Salomon.

(9) Orientation table at the top of the tower. *: Dolmen d'Adolphe Joanne and viewpoint on the left. *: Tortue du Cassepot. -: Belvédère Guérin and its cave below.
A little after the Tour Denecourt crossroads, the fountain circuit. The Touring Club de France fountain, built in 1901. The Désirée Fountain (with table) created in 1838 by Achille Marrier de Bois d'Hyver, the forest inspector who reorganised the Fontainebleau forest and named this fountain after his wife. It is dominated by a belvedere with a viewpoint. The Dorly Fountain, built in 1853 and named after a patron of Denecourt. The Isabelle Fountain, dedicated to the daughter of the sculptor Adam-Salomon, created in 1837. The sponge rock is made of calcareous sandstone. The holes are caused by rain, which has dissolved the limestone, leaving a honeycomb structure reminiscent of a sponge. Note: these fountains do not collect water from a spring, but from runoff from the rocks above.
At the exit of the fountains: Colinet Cave with stele. I: Oudry Rock, J: Le Gay Rock.

(11) O: The Leviathan. P: "N'y entrez pas" cave. Q: Mastodontes tunnel. R: Biera beer. S: Rocher des Marsouins. Bouquet d'Amélie (sessile oak to be seen on the way back).

(12) View from the Calvary Cross. Look to the left, in front of the railway viaduct, at the large white building: the former Hôtel Le Savoy. It was designed by Édouard NIERMANS, who also designed the Hôtel Negresco and the casinos in Nice and Monte Carlo. In the heyday of Avon as a holiday resort, before the First World War, European royalty, such as the King of Spain, would occasionally stay there, reserving an annexe behind the hotel. This Art Nouveau building was converted into apartments in 2000. It is a listed building.
Returning to the Blue: *: Calvary Shelter. T: Calvary Cave. U: Cyclops Parade. X Benjamin Cave.