The fortress of Blaye was built by Vauban in the 17th century. King of France Louis XIV wanted to protect the city of Bordeaux from a possible English attack. Therefore, Vauban decided to improve the medieval fortifications and, in order to completely close the estuary, he also built Fort Pâté on an island facing the Citadel of Blaye and Fort Médoc on the opposite bank. These three forts and the Vauban’s system of defence are listed as World Heritage by the UNESCO.