The Vieux-Port (Old Harbour), is at the heart of La Rochelle. Enclosed by its mighty medieval towers (Saint Nicolas and La Chaîne), the picturesque harbour is now lined with seafood restaurants and bars.
Since the 13th century, the port of La Rochelle has occupied this site. It is likely that from the beginning it was fortified. The remaining towers date from the 14th and 15th centuries. They survived the destruction of the enclosure after the siege of 1628. On each side of the entrance, the Saint Nicolas tower, the highest, and the La Chaîne, and further on, linked to the latter by a curtain wall, the Lantern tower, both a lighthouse and a prison.
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.