In reply to George Fisher:
We have stayed in Chateau Landon for our last 2 font bouldering trips, its about 30-40 minutes drive south of Fontainebleau, but being just that bit further from Paris the town feels much more chilled more like a village The town is set on high on a plateau looking out over a country park which can be accessed either by a hairpin paths/roads or ancient stone staircases. The park has a play area, nature trail, a small river/stream crossed by many small bridges, and some friendly donkeys.
There are several restaurants in the town this year we ate at the Cheval Blanc which does traditional French food. There are 2 Boulangerie a café, pharmacy, organic mini-mart and a butcher within walking distance, there is a small supermarket on the far side of the town.
we stayed at https://www.cheznous.com/279354/chateau-landon-house-seine-et-marne.aspx
My kids loved the games room in the basement, the cupboard full of games in the lounge and the enclosed garden.
The closest bouldering and walking in the "forest" is at Elephant or Dame Jouanne 25 minutes drive.