The Old Town of Visoki was a medieval royal castle town built during the 14th century on the top of the hill overlooking town of Visoko, Bosnia and Herzegovina. The first mention of the town was on 1 September 1355, in the charter 'in castro nosto Visoka vocatum' written by Tvrtko I of Bosnia while he was a young ban. The town was abandoned before 1503, because it is not mentioned in the Turkish-Hungarian treaty from the mentioned year. In 1626, Đorđić mentioned Visoki among abandoned towns.
The Old Town of Visoki is at the top of Visočica hill, 213 metres high. Its position provides an excellent view at the plains below. The entry to the castle is on the southwest side, with two lookout towers. Passing through the entry you enter to a part that is called Podvisoki, i.e. to the town that was quite small, measuring 60 by 25 metres, and has signs and remains of early medieval houses. The thickness of the castle town walls is about 2 metres. Its position provides an excellent view at the plains below bordered by mountains Romanija, Jahorina, Treskavica and Bjelašnica in the east and southeast, Bitovnja in the south, the mountain Zec and Vranica in the Southeast, Vlašić in the west, and Tajan and Zvijezda in the north. The entry to the castle is on the southwest side, with two lookout towers.
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.