Carmarthen Castle was first built by Walter, Sheriff of Gloucester in the early 1100s. It was captured and destroyed on several occasions before being rebuilt in stone during the 1190s. The castle was captured by Owain Glyndŵr in 1405. Henry VII's father died at Carmarthen Castle in 1456. During the Wars of the Roses the castle fell to William Herbert and, during the Civil War, was captured by Parliamentary forces. It was dismantled by order of Oliver Cromwell in the mid 1600s.
It has been used as the site of Carmarthen's gaol until the 1920s. The remains of the castle were given a Grade I heritage listing in 1954 and is currently a tourist attraction and site of the town's Tourist Information Centre.
The castle is accessed today via the surviving 13-metre-high gatehouse on Nott Square or alternatively via the Old Castle Gaol entrance on Castle hill.
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.