The Carnac stones are an exceptionally dense collection of megalithic sites near the south coast of Brittany in northwestern France, consisting of stone alignments (rows), dolmens (stone tombs), tumuli (burial mounds) and single menhirs (standing stones). More than 3,000 prehistoric standing stones were hewn from local granite and erected by the pre-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 BCE, but some may date to as early as 4500 BCE
According to Neil Oliver's BBC documentary A History of Ancient Britain, the alignments would have been built by hunter-gatherer people ("These weren't erected by Neolithic farmers, but by Mesolithic hunters"). That would place them in a different category from Stonehenge in England, which has been claimed to be the work of Early European Farmers.
There are several dolmens scattered around the area. These dolmens are generally considered to have been tombs; however, the acidic soil of Brittany has eroded away the bones. They were constructed with several large stones supporting a capstone, then buried under a mound of earth.