Saranta Kolones ('Forty Columns castle') is a ruined medieval fortress inside the Paphos Archaeological Park. It takes its name from the large number of granite columns that were found on the site and probably once formed part of the ancient agora. The Byzantine castle is believed to have been built at the end of the 7th century AD to protect the port and the city of Nea Pafos from Arab raids. It was later remodeled by the Lusignans in the early 1200s.
The fortress had a three-metre thick wall with four huge corner towers and another four intermediary towers along the joining walls and moat surrounding the castle. Access was across a wooden bridge spanning the moat. The square courtyard measured 35 metres long by 35 metres wide, with a tower at each corner. The main entrance was through a fifth, horseshoe-shaped tower on the east side. Destroyed by an earthquake in 1222, the castle was subsequently abandoned.
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.