Spine Castle was built in the late 12th century and destroyed in 1348. In the 16th century the castle ruins was converted into a hunting lodge. In 1933 a serious fire almost led to complete destruction, only the southern buildings were saved while the other wings collapsed and were never rebuilt.
Today only part of the castle is habitable while the rest lie to ruins, although impressive. Spine castle is not open to the public.
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.