San Leonardo de Siponto monastery was founded probably between 1113-1127. The hey day was during the late 12th and early 13th century. In 1261 it was moved to the hands of Teutonic Order. In the 18th-19th centuries it was left to decay and dissolved in 1809. Today restorations are going on.
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.