No special access issues
🅿️
Park on either marked parking. The one on the east side is closer, but has an height barrier of 1.9m, there are though a couple of parkings outside the barriers. The one on the west side is closer to Télégraphe and Hameau, but it's not more than 10 minutes of a walk to the main part of Nainville. There are plenty of marked good paths on the map. Stick to the paths and behave as usual.
🚶
If parked at the east side, you will find the first boulder literally 3 meters from the parking. That's where one of the kids white circuits starts and just behind this small boulder, you can find the start of the Yellow circuit.