The hill on which the fortress is located is known as St. Petka, and the name Peristera (pigeon, pigeon place) is mentioned for the first time by Ivan Popov in his study “Pages in the Past of the Cave”. The following legend has been preserved about the origins of the fortress: “When Christianity was introduced in the Byzantine Empire in 313, the local inhabitants had to choose which of the hills in the area to build their church, so a flock of pigeons flocked from the holy St. Petka” . The archaeological study has made it possible to elucidate almost entirely the history of St. Petka Hill. In the highest part of the hill are grouped stones of different sizes, one of which is a dove. This fact gives reason to assume that the place was known as holy still to the Thracians, who made it a sanctuary. The fortress “Peristera” occupies the entire hill “St. Petka” and has a clearly differentiated citadel, inner city and suburb, located on an area of about 15dka. For now, the fortress walls of the citadel and the inner city have been clarified and restored. Perhaps the suburb is partly covered by the modern streets and buildings of Peshtera, including the Pazardzhik-Peshtera road, where there was a gate with an arch, directly below the fortress. The modern architectural reconstruction of the fortress system of the Peristera citadel is entirely based on the results of an archaeological study, while adhering to the authentic appearance of the late antique facility.