Carnac
Carnac, a village near the Atlantic coast of Brittany in northwestern France. Carnac is famous as the site of more than 3,000 prehistoric stone monuments. The single standing stones (menhirs) and multistone clusters (dolmens) were hewn from local granite, now worn by time and weather and covered with white lichen. The stones were venerated by the Bretons (the Celtic people of Brittany).The Megaliths were erected during the Neolithic period which lasted from 4500 BC until 2000 BC.
The three main structures of the megalithic architecture are "Menhirs" and "Dolmens" and "Tumulus". Dolmens and Tumulus were burial structures, they were either collective or individual tombs. Menhirs means an army of stones There are approximately 3000 menhirs in the Carnac area. The alignments probably had a cultural role and were a place of worship.
Archeologists think that the Dolmens - artificial caves built of stones and stone plates - were made for burial purposes. For the standing stones - the menhirs - there isn't any reasonable explanation.