Bayonne has been inhabited since roman times, when it was known as Lapurdum. Its medieval fortifications were improved by Louis XII, and Francois I, enabling the town to defend itself against a Spanish army in 1523.
Vauban visited Bayonne sometime in the 1670's, and planned more improvements to the fortifications, including the construction of additional demi-lunes and a large, quadrangular citadel to the north of the river Adour. The city itself, which lies to the south of the Adour and is bisected by the river Nive, was surrounded by a wall of 9 rather eccentric bastions.
The citadel was designed from scratch by Vauban, and is a large square work with four bastions. It saw action against the invading British forces at the end of the Peninsular War, when it was taken by General Hill after a determined defence by the French.
The fortifications of Petit Bayonne, the eastern half of the town, had four bastions and one gate, the Porte de Notre Dame. To the west, Grand Bayonne had five bastions and two gates, the Porte d'Espagne and the Porte de la Poterne. The first gate is unusual in that it enters the walls through a bastion, not through the courtine as is normally the case.
The size and shape of each bastion is very different, and there are varying lengths between them, which makes the fortifications seem less regular than some. This is probably due to the way Bayonne was fortified in several stages, with improvements added gradually.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.