Start: Fontainebleau-Forêt railway station (see practical information for days and times).
(S) From the railway line, take the Blue-Yellow marked trail no. 15 heading north. Cross several perpendicular paths (follow the markings carefully) and arrive at the Tour de Samois (unfortunately, you cannot climb it).
(1) At the tower, turn right onto the flat path (do not head down towards the town) then, 10 metres further on, turn right downhill, still following trail no. 15.
(2) After a right-angle left turn, at the junction with path no. 13, continue on path no. 15, turning left, heading north then east.
Pass the Samois forest house, cross the road and turn left almost directly opposite. At the top of the stairs, admire the view of the Seine, then turn right (south-west).
At the first house, veer slightly right into the forest. At the roundabout, cross the D137 road (north-west). Stay parallel to the D138 until you reach the railway bridge. Cross both the road and the bridge, then take the forest track to the left (south). After about ten metres, turn right into the forest, heading west (signpost 13-15).
(3) At Cassepot, join theGR®1Eand follow it west-north-west. Go round the Dénécourt Tower on the right. You can climb the tower to admire the view.
(4) Opposite the path leading to the tower, you’ll find three paths: take the one furthest to the left, the Chemin Dénécourt No. 2 (blue markings), heading west.
(5) After about 150m, turn left downhill (south), blue markings 2. At the Tour Dénécourt junction, let theGR® head due south; stay on the blue-marked path and turn south-west.
The marked path takes us in turn to the Touring Club, Désirée, Dorly and Isabelle fountains. After the latter, you’ll come to the Roche Éponge, a strange rock formation that looks as though it’s perched on a platform. Turn back.
(6) Take the path that passes above the Isabelle fountain to the left (west-south-west). Cut across until you reach the blue-marked path no. 2, which you will take to the right (west). Pass the Croix du Calvaire (view), then continue along the blue trail no. 2 which heads into the forest beneath the edge of a plateau with shelters. 150m after the cross, two successive junctions that are quite confusing.
(7) At the first, head up to the right (north-west) between the rocks, following junction 2-2.
(8) At the second, continue straight ahead on level ground (north-west) on junction 1-3. In both cases, follow the signs for “Croix d’Augas”. Pass the Auberge de la Croix d’Augas (though no cross is visible), cross the D116.
(9) Continue north-north-west, following blue signpost no. 3.
(10) At the junction of roads 257/250/249/Route de la Butte à Guay, continue straight ahead (Blue signpost no. 3). At the junction of roads 249/243/244.
(11) Do not take the Route de la Vallée de la Solle but head slightly back towards the left (north), following Blue signpost no. 3 (signposted Rocher Cassepot). Pass by Les Mares Froideau.
(12) Rocher Cassepot viewpoint. Continue following the blue markings along the cliff edge.
(13) About 600m further on, at the junction with blue trail no. 14 (which descends to the right), continue straight on along no. 3.
(14) 100m further on, turn right onto the blue trail no. 4-3 (West-North-West). Follow the markings carefully to cross the busy D606 road. Cross the Cabaret Masson site following the blue markings 4-3 (West). 200m past the road, you’ll reach the junction with the Dénécourt Blue Trail No. 4.
(15) You can take either the right-hand path (more scenic, rockier) or the left-hand path (easier, saving 15 mins), signposted towards the Grotte aux Cristaux and the Belle Croix car park: this is the route shown on the map.
(16) At the Grotte aux Cristaux, take the path leading uphill opposite towards the car park. Cross the D142 (westbound, unmarked). About twenty metres past the road, turn left onto a path between two hedges of brambles (south), which quickly joins the Route de la Mare à Piat: follow this westwards. You’ll arrive at Mare à Piat, a quiet spot, magnificent with its water lilies.
(17) Continue along the path towards the north-west. At the junction 879/880/881 with the Route Tournante du Cuvier-Châtillon (elevation 137), take the path on the left (south-west).
(18) Pass the pond at Dagneau, then continue along the path which leads into the forest (south).
(19) On a plateau ledge, join the Blue Trail No. 5 and follow it to the right (west). Pass the Mare aux Canards.
(20) At a dead-end on a plateau, the blue path descends to the left: ignore it and take the path that descends a valley on the right-hand side (northwards), passes the sign “Reconnaissance — Colinet”, and joins the Route du Cuvier Châtillon heading north, and finally theGR® and the TMF (green and white markings). Head back up onto the plateau.
(21) On the flat, cut left and follow the Route de la Table du Grand Maître (north-east). Join theGR®+TMF at the next junction, turn left onto the Route des Monts de Faÿ (north). Follow this road for 800m.
(22) Just as the road begins a steep descent at the edge of the plateau, turn left (west) onto the Blue trail no. 12. The Blue trail curves north-west, then makes a wide circular loop to the right before heading east again.
(23) At the Massif du Rocher Canon, leave the blue trail and take a faint path to the left that passes between two flat rocks. Head north to the Chemin du Lancer, which you take to the right (east). Continue straight ahead. In Bois-le-Roi, head to the station (E) (trains to Paris every 20 to 30 minutes).
) and completed it in 10 hours, getting lost in the rocks at times and having to retrace our steps, so do allow a bit longer than the 7 hours mentioned. And make sure you have a full-scale map, because it’s easy (though not unpleasant) to get lost in the ferns – IphiGénie, the brilliant IGN app, proved incredibly useful. But once again: a wonderful hike.