Castle of the Dukes of Alba was founded in the 12th century when King Ferdinand II of León ordered to build a simple watchtower. In the 13th century, King Sancho IV of Castile converted the primitive tower into a castle. It was devastated by the battles of the time of King Henry IV of Castile but later rebuilt and converted it into a private palace.
In its interior you can visit several rooms, such as the one that houses the mural paintings of the Battle of Mühlberg.
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.