Fort Lupin, also known as Fort de la Charente, is an artillery battery in Saint-Nazaire-sur-Charente, in the department of Charente-Maritime. It was built in the 1680s to a design by Sébastien Le Prestre de Vauban, and it is now in good condition.
The fort consists of a semi-circular gun battery ringed by a parapet with twenty-two embrasures. A tour-réduit and two blockhouses are located at the gorge. The fort is further protected by a ditch, a covertway and a glacis.
Fort Lupin was never attacked, and it never fired its guns in anger. It was decommissioned in the late 19th century, and was subsequently abandoned and vandalized.
The fort was sold to a private owner in 1964. The owners have restored the fort, and today it is in good condition. It is not open to the public on a regular basis.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.