The circuit follows the Denecourt-Colinet trail N°2 (blue markings).
SNCF train station - Croix du Calvaire = 1.5 km
At the train station’s square, first head towards the station buffet and then go up the road with the drop-off point 30 away to take the second staircase to access Avenue Franklin Roosevelt. Cross at the pedestrian crossing which is opposite the cafe “Le Terminus” and continue straight ahead. 15 metres further on, cross Rue de la Bonne Dame and take path N°2, which begins just to the right of the beginning of Route de la Reine Amélie. It climbs into the forest following the contours of the the old Avon pool. It cuts Route de la Reine Amélie 2 times in the rise at a sharp bend hairpin. This is also where cars are forced to stop because the forest road is blocked. Just after the dirt car park, the trail passes near a large rock on which has been affixed a Nemorosa medallion then continues as an “overhang”. 200 metres further on (1), veer to the left towards the Croix du Calvaire. Cross back over Route de la Reine Amélie back to first path in the middle of some pretty rocks and into the undergrowth to the viewpoint for Croix de Calvaire (2).
Croix du Calvaire – Denecourt Tower= 2.5 km
Leave the cross behind to follow the paved road for about ten metres and then, just after the bench, take the trail on the left. The route quickly leads close to a large rocky “shelter”, the Abri du Calvaire, although access is not permitted because it threatens to collapse. Then the path heads into a little rocky maze leading to the exit where you turn right to go up on the plateau at the lookout point over the Ravine. Another fork Stay on path N°2. It leaves towards the north - north-east to Denecourt Tower. As far as the junction with Route de la Butte à Gay, it is almost straight and flat as it follows Route du Calvaire which is the extension of the Route de la Reine Amélie. We cross the intersection (3) and the path starts to descend until it reaches the Jean Bart crossroads where we meet the eponymous road, also closed to cars. On the other side the path leads up to join the trail from the Cassepot Rock, and reaches the top of the hill through large blocks of sandstone. Head on to Denecourt Tower (4). Climb on up to get an interesting view over the Seine valley.
Denecourt Tower- Sponge Rock = 4 km
We leave the tour continuing on path N°2 towards the "fountains" (fontaines) and the railway station. The path first turns to the north among the rocks before turning westward down the hill to reach the crossroads of the Denecourt Tower (5). Here, the paved access road to the tower joins Route Jean Bart road, both of which are closed to traffic. Cross the intersection and follow the path that remains virtually flat for 600 m before climbing in 2 loops up the plateau edge. The trail winds along here for a time. From time to time, you might notice traces of ancient quarry works that operated on the sandstone (paving, small trenches, piles of stones, etc...). The first "fountain" that you will come across (6) is on your right, in the hollow of a rock (Fountain of the Touring Club of France). Less than 80 metres away is the “Desiree fountain" with benches and a table in sandstone installed in front of it. 400 metres further on, in the hollow of a small sandstone wall along which the trail runs, the Dorly Fountain can be accessed by a small staircase. The path then deviates from the shelf edge to cross Route Baudrillard. It runs through the middle of the ferns and reaches Isabelle fountain, the last of the hike. The path then turns left to reach a clearing where the Sponge Rock (7) is located.
Sponge Rock - SNCF train station = 1 km
From there, you reach the station still following the path N°2, which is close to the Queen Amelie road while settling back on the shelf edges. Finally, come to the outbound path (1) to reach the Croix du Calvaire. Then return to the rock with the Némorosa medallion and the descent to the train station by the old pool.
A good walk.