2 Espl. de la Citadelle, 33390 Blaye, France
Blaye CitadelAn entire group of structures by Louis XIV’s great 17th-century military architect and engineer Vauban are UNESCO World Heritage Sites. With four bastions surrounding 90 acres of terrain, Blaye Citadel is the major fortress in a trio that includes the Fort Paté on a small island and Fort Médoc on the left bank. Like a rope strung across the Gironde, together they offered a formidable defense against any foreign navy unwise enough to try to head upriver.