Carnac, found on a narrow peninsula halfway between the medieval town Vannes and the seaside resort Quiberon, is split into two centres - Carnac-Ville and Carnac-Plage (the beach front). In total there are five beaches, including la Grande Plage, and further to the east, Plage Men Dû and Beaumer.
The Carnac stones were erected during the Neolithic period which lasted from around 4500 BC until 2000 BC. The precise date of the stones is difficult to ascertain as little dateable material has been found beneath them, but c.3300 BC is commonly attributed to the site's main phase of activity. One interpretation of the site is that successive generations visited the site to erect a stone in honour of their ancestors.
In 1903, a seaside resort was created on the old salt flats, developing extensively through the 1950s to create the split Carnac of today: Carnac-ville and Carnac-plage. In 1974, a renowned hydrotherapy centre was sponsored by champion cyclist Louison Bobet, retiring after having won the Tour de France three times from 1953 to 1955.
Since the end of World War II, Carnac has become a popular site for tourists seeking a break from the traditional destinations on the Côte d'Azur. During the months of July and August, the number of people in the town swells from the influx of tourists and summer home residents. The beaches of Brittany are rarely able to offer warm waters on par with those of their southern cousins; however local factors have ensured that Carnac continues to be a touristic boom town. Wind and waves in the region attract day and cruise sailors. The Standing Stones and other monuments in the vicinity provide a modest degree of cultural attraction while Carnac-Plage's variety of bars and clubs ensures that a younger set can amuse themselves at night.
There are a number of camping grounds in the woods around Carnac, some clustered around various lakes such as the Étang du moulin du lac which is immediately to the west of the river Crac'h.
Carnac is home to "École de Voile de Carnac" which provides sailing and windsurfing lessons and rentals to sailors of all experience levels. The geography of the Bay of Quiberon provides ideal conditions for sailing. The Peninsula of Quiberon provides protection from Atlantic waves and turbulence while allowing the Gulf Winds to enter the bay.
For windsurfers, the Saint-Colomban beach located in Carnac-Plage. The beach is very popular with windsurfers, as its position allows for the best exploitation of strong winds from the West. Other beaches in the area provide equal access to the winds of the bay but windsurfers may find themselves frustrated the areas of dead air close to their shores.
As of the census of 1999, the town has a population of .