Many thanks to TheCaptain at The Megalithic Portal and to the Megalithes du Monde for assisting me in finding the last great french mystery dolmen - now properly identified as Dolmen de la Pierre-Folle:
As I continue to sort through my snaps of France I came across this one:
We were staying at a lovely gite in Haute-Normandie - Eure. The owners were most eager to help us in our search for 'stones' and came up with a map and marked where at the bend in the road we would find this treasure. Truly over the hills and through the woods....
My searching has lead me to a near match by the name of Pierre Courcoulée (posted by TheCaptain, again) but I am not so sure it is the same site....
Confirmation anyone?