Allée couverte dite de Coguer Neguinan

In an area on top of a hill overlooking a stream is the ancient hamlet of Le Palastre. I found quite a few stones here, but was not sure what the official dolmen is ! In the front of somebodies garden right in the centre of the hamlet, now made into a nice garden feature, are these three aligned stones - perhaps once a part of an allee couvert, or some other monument.