Alanís castle has Arab origins. The town was conquered by Ferdinand III in 1249 and the castle was rebuilt in 1392. It has a hexagonal floor plan, with a tower and barbican, which has now disappeared. Its walls are 2.3 metres wide and 6.5 metres high, leaving only one access to the enclosure on the north side, from where the village can be seen.
Th castle was attacked by the French during the Napoleonic occupation, who dynamited one of its walls, the southwest one, and the ruins are still preserved today.
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.