Castillo de Moguer was renovated and enlarged in the 14th century. The oldest record document of castle dates from 1362, but it probably existed already in the Moorish age.
The castle was built of mud-based mortar gravel, clay and lime. It is of an imperfect square plan 44 by 45 metres in size, with four towers at the corners. A moat surrounded the castle, as evidenced by written records, but is not currently visible. Access to the castle was across the northwest side, now Santo Domingo Street, via a ramp. Each tower measures 9 by 9 metres and contains two chambers with a covered brick dome. The four towers were topped by battlements. A cellar dating to the 18th century, measures 22 by 10.5 metres and serves as the headquarters of the Tourist Office.
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.