A Kale Fortress is a smaller fortification with towers and walls. The fortress consists of three parts: the upper town with a donjon tower, the middle part with a rampart and two towers, and the lowest - the lower town with a rampart and a brick moat.

Through different time periods, the fortress had different names, TURRES (tower), Pyrgos, Thurib, Momčilov grad, and Kale, which are most commonly used today. Archaeological research of the middle part of the city of Pirot revealed that there was a settlement in that place as early as 5,000 years ago, and other traces from the Eneolithic and Iron Age, Antiquity, early Byzantium, and the Middle Ages were also discovered.

It is related to the period of Duke Momčilo's rule, so it is also called Momčilo's Town. It was built during the reign of Prince Lazar Hrebeljanović (1371-1389). The Ottomans managed to capture it, but in 1386 it was recovered by Duke Dimitrije, which was one of the reasons for the Battle of Kosovo in 1389.