The excavation located in Carhaix-Plouguer (Finistère, France), Kergorvo-Kerconan, concerns quarries dating from Neolithic to first Iron Age and a little group of Roman burials. A geophysical survey preceded the excavation. Quarries consists in broad pits – the largest measures close to 40 by 10 meters. As they are all settled in sandstone (grauwacke's) layers, they are interpretated as open quarries. Based on radiocarbon dating, the exploitation of stone could begin at the end of the middle Neolithic to the first Iron Age, probably with breaks in the use. At last, six burials dating from the 1 st to the 3 rd century AD have been discovered in final filling of one of the main quarries; they illustrate a long long occupation in this part of the middle-west of Brittany.