According a tradition there has been a defensive complex here since pre-Roman times. The Rocca fortress was built in the late 12th and early 13th centuries. The last military operation took place in 1510 and after that Rocca was moved as hospital and private use.
The fortress was involved in his latest war episode in 1510 . Gradually Persa's strategic importance, the structure was used as a variety of uses also becoming hospital during the continuous plagues of the sixteenth century. Decommissioning in 1650 , Venice even tried to sell it to private.
The massive construction has a polygonal plant of nine unequal sides. There are no open slits or windows: only one door gives an access to the upper defensive system of the city.
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.