Despeñaperros Castle also known as San José Castle, is a castle built in the 18th century in the historic center of Cartagena, Murcia Region in Spain. It was declared a cultural site on 7 August 1997. The walls are composed of masonry and generally flat. The interior of the fortification is divided in two perimeters, the lower with rooms for the occupants and a water reservoir, and an upper space occupied by the cannons, and which has lost gunships.
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.