The tumulus of Saint-Michel was constructed between 5000 BC and 3400 BC. At its base it is , and is high. It required of stone and earth. Its function was the same as that of the pyramids of Egypt: a tomb for the members of the ruling class. It contained various funerary objects, such as 15 stone chests, pottery, jewellery, most of which are currently held by the Museum of Prehistory of Carnac. It was excavated in 1862 by René Galles with a series of vertical pits, digging down . Le Rouzic also excavated it between 1900 and 1907 discovering the tomb and the stone chests.