Well the map said this was destroyed and indeed it is. Quite a bugger to find too with my two incompatibly scaled maps. In many ways though it's still worth a visit.
Set on slightly higher ground and hence, this being the Norfolk of France, commanding views of all around. The dolmen is now a low mound around 11m long by 5m wide. A number of large stones lie upon and within this mound including at least one former capstone. The others may be the collapsed walls; although for all I can tell there may still be a chamber within.
I am realizing that this area may not be the megalithic metropolis it appears at first glance on a map but these small, sadly ruined, sites have a personal air lacking at some more impressive sites. And it feels more like real antiquarianism hunting them out too!
The mound is orientated around 340°-160°.