Des Gorges de Franchards near Fontainebleau

This place is seriously great. We first discovered it while hiking through the forest and it was full of people (it must have been the weekend) but during the week it is usually quiet. 

Great parking, a big field that always seems to have huts build around the edges, paths through the rocks and forest. Good for playing find the next trail marker and generally climbing around. Right up the road from Site Arbor & Sens.