Boissy Norgevaux
First of all, this is a hunting area. So during hunting season avoid this area(october - beginning of march) .
It's a quiet 2 boulder area. The main attraction is the boulder kong and king. There would be an almost endless amount of variations available on this boulder, but let's keep this "as clean" as it's now. The parkings on the small road are only for 1 car and the road is far from perfect. It's also a rather simple walk from the main road.
The reception is okay at the boulder, but offline can still be handy for loading map. Stick to the path which takes you basically directly to the boulder.