Cafarlet or Capharleth (Crusader name) or Kafr Lam (Arabic name) is an Early Muslim coastal fortress of the Roman castrum type. Today it is located inside Moshav HaBonim, Israel, on lands of the now abandoned Arab village of Kafr Lam. It was built in the 8th or 9th century, during the Umayyad or Abbasid period to serve as a ribat against Byzantine attacks, and was significantly modified and reused by the Crusaders. It is one of the few surviving ancient fortifications in Israel featuring round watchtowers, indicating the fortress' origins predate the crusader era. Most surviving ancient fortifications in the region feature rectangular watchtowers, typical of the style prevalent in Europe during the time of the crusaders.
References: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.