The Château de Hohbarr (Haut-Barr) is a medieval castle, first built in 1100, above the city of Saverne in what is now the French département of Bas-Rhin. It was built on sandstone rock 460m above the valley of Zorn and the plain of Alsace. Because of this, it has been called the eye of Alsace.
The current castle was built in 1583 by Jean de Manderscheid. The Peace of Westphalia mandated the destruction of several castles, including Hohbarr, but after the beginning of the War of the Spanish Succession, in 1701, the fortress was back in use. It was abandoned around 1770, but the vault continued to be occupied until the French Revolution.
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.