Brittany has also been referred to as Less, Lesser or Little Britain (as opposed to Great Britain, with which it shares an etymology).[2] It is bordered by the English Channel to the north, the Celtic Sea and the Atlantic Ocean to the west, and the Bay of Biscay to the south. Its land area is 34,023 km² (13,136 sq mi).

Brittany is the site of some of the world's oldest standing architecture, home to the Barnenez, the Tumulus Saint-Michel and others, which date to the early 5th millennium BC.[3][4] Today, the historical province of Brittany is split among five French departments: Finistère in the west, Côtes-d'Armor in the north, Ille-et-Vilaine in the north east, Loire-Atlantique in the south east and Morbihan in the south on the Bay of Biscay. Since reorganisation in 1956, the modern administrative region of Brittany comprises only four of the five Breton departments, or 80% of historical Brittany. The remaining area of old Brittany, the Loire-Atlantique department around Nantes, now forms part of the Pays de la Loire region.