The Castle of Monopoli, surrounded by the sea and located on a peninsula, was built first as a stronghold and later changed into noble house. It was originally built as part of coastal strongholds by Holy Roman Emperor Frederick II and later fortified by the Angevins. In 1552 it was once again reinforced by the viceroy Don Pedro de Toledo, at the behest of Charles V. Other important changes were made in 1660, by the Duke of Atri Giovanni Geronimo Acquaviva.
The present appearance dates back to 1660, when the huge cylindrical keep was added, from which it is possible to enter. On the upper part, there are large holes for the cannons, a sign of the original function to protect the town, while the right part, towards the town, appears to be more refined after the works of the 17th century, when it started to be used as house.The castle, reshaped several times over the centuries and used as prison during the first years of the 20th century, was restructured around 1976 and nowadays houses the Archaeological Museum of the Town.
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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.