Nicopolis ad Istrum was a Roman and Early Byzantine town. It was founded by the Roman Emperor Trajan after his victories over the Dacians in 101 and 106. It was built over an area of 30 hectares and is surrounded by fortress walls. The villas the craftsmen's workshops and necropolises are to be found outside the walls. The town was planned according to the orthogonal system. The network of streets, the forum surrounded by an Ionic colonnade and many buildings, a two-nave room later turned into a basilica and other public buildings have been uncovered in this town.
The rich architectures and sculptures show a similarity with those of the ancient towns in Asia. Nicopolis ad Istrum minted its own coins - 900 different emissions for one century, bearing images of its own public buildings. It was an episcopal centre during the early Byzantine period and was destroyed b the Avar invasions at the end of the 6th century. A Bulgarian medieval settlement arose upon its ruins later (10-14th century).
Nicopolis ad Istrum is an important site and is visited by thousands of Bulgarian and foreign tourists and many specialists. It has been declared a monument of culture and scrupulous care is taken of further excavations, investigation and popularization.
The site was placed on the Tentative List for consideration as a World Heritage Site by UNESCO in 1984.
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.