The structure is perched on an elongated terrace at the foothills of the most northeastern ridge of the Rhodope Mountains known as Gorata or St Marina.

[3] Mezek Fortress is situated at an altitude of 210 m next to the homonymous village in Svilengrad Municipality of Haskovo Province, southeastern Bulgaria.

[1] Mezek Fortress encloses an area of 7 decares in the shape of an irregular quadrangle measuring 110/60 m.[1] The walls are constructed of rubble stone joined with white mortar and decorated with three brick belts on the outside.

The floors were open to the interior of the fortress so that they had a circular fire range and could be defended even when the enemy penetrated the fortification.

According to Choniates, this deed greatly encouraged the Bulgarian rebels, who had feared Constantine's ability and much preferred the ineffective Isaac II to remain on the throne, if possible, forever.

[7] The battlements of the fortress were intact until 1900, when part of the structure was demolished by the Ottomans in order to reuse the stones for the construction of barracks in Svilengrad.

The first archaeological research of the fortress was carried out in the 1930s by architect Aleksandar Rashenov, who performed excavations, documentation of the fortification system and small-scale studies of the interior.

Based on the data, the construction of the fortress was dated to the end of the 11th and the beginning of the 12th century,[3] probably during the reign of Byzantine emperor Alexios I Komnenos.