Construction of the fortress by Mezek village dates back to the end of ХІ and the beginning of ХІІ c., probably during the reign of Byzantine Emperor Alexius I Comnenus (1081-1118). It was very well preserved until the beginning of XX c. when rocks from the fortress were used for construction.
The fortress has the shape of an irregular tetragon. The defence was carried out through nine towers. In the most vulnerable southern side there are five towers altogether (two corner towers and three more on the front line). The western side where the main entrance of the castle is situated, the towers are two in number. The eastern and the northern sides, that are well guarded due to the character of the terrain, dispose of one tower per each. Regarding its arrangement, the situated on the south-west tower is the most interesting one. It has had three storeys separated by trimmer joists and the upper two storeys have had portholes.
The first research studies were made in the 30-ies of the twentieth century. The excavations have revealed a large quantity of fragments of pottery, stone crushers and other objects of daily life, jewelry, etc. In 1937 and 1983 two granaries with charred grain were found during examination of the place.
The mediaeval fortress by Mezek village is situated on the south-east of Bulgaria, 12 km to the west of Svilengrad. In order to get to it from the square of Mezek village go to the north-west following the main street. Skip the first turning on the left, turn on the second one. The road goes out of the village and in 500 m you will reach the tourist information centre. After that comes the fortress.