|Length||125 metres (410 ft)|
|Width||60 metres (200 ft)|
|Height||10 metres (33 ft)|
The tumulus was built during the fifth millennium BC.
The Saint-Michel tumulus consists of a mound of earth and stones 125 metres (410 ft) long, 50 metres (160 ft) wide and 10 metres (33 ft) high. Explored in 1862, researchers found there a central vault containing fairly prestigious funerary furniture : axes, pearls, flint tools and sillimanite.
Around 1900, the archaeologist Zacharie Le Rouzic again excavated the Saint-Michel tumulus and discovered a second dolmen and fifteen small stone chests, thus revealing the complexity of this monument.