Although this is listed as a historic site because of its menhirs, the boulders in the background are possibly far more interesting. They definitely bear resemblance to the style of megaliths called cyclopean on this website and should be studied from that point of view. There is some change that they are ruins. Otherwise the full area is very rich in all kinds of relatively more recent megaliths of all kinds and description. Viewed separate the boulders in the background look rather natural, but if you view all the other cyclopean megaliths a different prospective will emerge.