The Carnac stones (Breton: Steudadoù Karnag) are an exceptionally dense collection of megalithic sites around the village of Carnac in Brittany, consisting of alignments, dolmens, tumuli and single menhirs. More than 3,000 prehistoric standing stones were hewn from local rock and erected by the pre/proto-Celtic people of Brittany, and form the largest such collection in the world. Most of the stones are within the Breton village of Carnac, but some to the east are within La Trinité-sur-Mer. The stones were erected at some stage during the Neolithic period, probably around 3300 BC, but some may date to as early as 4500 BC.
Although the stones date from 4500 BC, modern myths were formed which resulted from 1st century AD Roman and later Christian occupations, such as Saint Cornelius a Christian myth associated with the stones held that they were pagan soldiers in pursuit of Pope Cornelius when he turned them to stone. Brittany has its own local versions of the Arthurian cycle. Local tradition claims that the reason they stand in such perfectly straight lines is that they are a Roman legion turned to stone by Merlin.
In recent centuries, many of the sites have been neglected, with reports of dolmens being used as sheep shelters, chicken sheds or even ovens. Even more commonly, stones have been removed to make way for roads, or as building materials. The continuing management of the sites remains a controversial topic.