La Maison des Fées at Tressé in the Mesnil forest of Bretagne, NW France. (The aerial view shows how deeply forested the area is!). I am glad to finally get color pictures and a more general view of the dolmen, named House of the Faeries. Countless megaliths were named as the House, Cabin, Hut, Oven of the Faeries, in France, and in other parts of western Europe.

https://monumentum.fr/dolmen-dit-maison-des-feins-des-fees-pa00090891.html?fbclid=IwAR10GUGLyUzGWDy230w99jKBeDjt5n23omuJs9pHG6-LjoqGVjgBtBehlS0

The faeries who lived in the monument one day let a cow escape and she trampled a nearby field. To recompense its owner the faerie offered him a piece of bread which never turned hard nor diminished, as long as he kept secret where it came from. It last for a longtime but the farmer eventually spoke of where it came from, after which the bread became too hard to eat.

https://fr.wikipedia.org/wiki/Maison_des_F%C3%A9es

There are two pairs of breasts, one on a stone marking out an entrance court, and another on a megalithic wall facing it.

Closeup of the exterior stone, with the left figure marked with an inverted crescent (possibly a diadem) and a slight curve marking her belly.

Above, a broad view of the entrance, and of the length of the megalithic passage, amidst the forest of Mesnil.

Back view of the dolmen, which would date to the early 3rd millennium bce or possibly the 4th.

Breasts were carved in relief on several other megalithic enclosures in northern France. They appear as ancestral guardians of burial places, probably in matrilineal contexts. Below, from an allée-couverte / "gallery grave" at Prajou.

More orthostat stones at Prajou. Some of the French relies show necklaces above the breasts, but others have U-shapes below them, as if outlining the belly or womb.

Face, necklace, and breasts, from Aubergenville.

La Pierre Turquaise, "Turkish Stone," in the Carnelle Forest.

There are actually two female ancestors engraved on the Pierre Turquaise:

Another ancestral woman in Aveny Dampmesnil, Eure department of northern France, showing overhead plan of the allée couverte. Here as at Tressé, the standing stone with its female guardian faces the entrance.