Tinboeth Castle is believed to have been built by Roger Mortimer during the 13th century. Following Mortimer's death, the castle fell into ruin and little of the structure remains. The castle was constructed in an Iron Age hillfort and measures around 100 metres in diameter. The Royal Commission on the Ancient and Historical Monuments of Wales notes that the remains indicate the site featured a twin-towered gatehouse on the north-east corner of the structure.
The outer bailey of the castle utilised the hillfort as a defence, while the inner bailey featured a stone wall which was accessed by the gatehouse.
An earthwork remains, believed to be the remains of a wall, but little stonework above ground except the collapsed remains of the gatehouse.
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.