Aracena Castle was erected in the 13th century, during the Islamic period, and was itself built on the site of an ancient Moorish castle. The walled enclosure was partitioned inside, with the tower of homage, or castle keep, defending the barrier that divided its interior. The population of Aracena settled around this structure, giving rise to the current urban landscape. During the late Middle and Modern Ages, Aracena continued growing from the Cerro del Castillo (castle hill) into the valley, first as unattached land dependent on Seville and later, in the seventeenth century, as a feudal estate under the jurisdiction of the Count-Duke of Olivares. Still later, it was under the Count of Altamira, who carried the title of Prince of Aracena.
The fortress consists of the alcazaba, or citadel, with its watch tower, cistern and walls; these are flanked by other towers, as well as a fence line that, in its interior, once accommodated medieval living quarters.
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.