From Paris, take the exit Auvernaux on the motorway and follow the D948 till the first crossing after Le Saut du Postillon. Turn right on the D83 in direction of La Ferté-Alais and 250m after, take an unpaved road on the right and park the car near the forest, just above the aqueduct (underground but visible at this place). The start of the circuits are 30m above the two ruined edifices (slightly further for the orange circuit which starts on a big boulder on the other side of a sandy path).

6a+

6a

5

5-

4+

4

4-

3+

3

3-

2+

2