Tauresium is an archaeological site in North Macedonia, best known as the birthplace of Byzantine Emperor Justinian I (ca. 482) and King Theodahad of the Ostrogoths (480).
Tauresium and the castle Baderiana were destroyed in an earthquake in 518 and the epicentre of the earthquake was in the nearby city of Skupi. As a gesture of gratitude to his birthplace, Justinian I rebuilt the city. According to the excavations that have been done so far, it is estimated that the oldest parts of Tauresium date from the 4th century and this oldest part is a castle with four towers known as Tetrapirgia.
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.