The Besac fortress is located above Virpazar, on a hill that stands out in the vast Crmnički polje. There is a road leading to it, with a separate path from the Virpazar – Bar road, via Sutorman. It was built by the Turks, immediately after the fall of Donje Zeta, in 1478. year, and kept it in their possession for the entire time of their presence in these parts. At the end of the 17th and the beginning of the 18th century, Besac was occupied by Montenegrins, when it suffered considerable damage. Since then, it has lost its importance and is only occasionally used. Between the two world wars, a gendarmerie station was located in Besac.

During World War II, the Italians used it as a prison. After that, it was permanently abandoned. Besac includes a plateau of 1200 m2, and is protected by ramparts, which follow the basic configuration of the terrain, so that the complex has the shape of an irregular triangle. It consists of a fortification with towers, a barracks building, a defensive wall with an entrance gate, observation posts and auxiliary buildings.

The construction was made of pressed, broken stone, richly immersed in lime mortar and arranged in relatively regular horizontal rows, with rough joints. The fortification itself has a rectangular base, with two circular towers, placed on two opposite corners. It consists of a vaulted ground floor and a first floor with openings for cannons. The building that served as a barracks, located near the entrance, has a rectangular base, with a gable roof. The ramparts are of different heights, depending on the terrain configuration. An observation tower was placed on two projecting corners, of which the one facing the lake had a floor and a vaulted underground part.