The Museum of the Old Cathedral at Serres was founded on the occasion of the reopening of the Byzantine church of Agioi Theodoroi (Old Metropolis) as a pilgrimage temple. The Byzantine sculpture from the monument itself was also thought to be worthwhile. The exhibition eventually developed in the northern facade of the monument and in the courtyard. Various sculptures that were once included in the sculptural decoration of the temple, as well as various tombstones, were exhibited.The surveillance material summarizes the history of the city, its fortification, and the history of the monument. In the courtyard sculptures and inscriptions of various eras from the city of Serres and its region were arranged on the walls and on the walls.

On the north side of the temple of Aghioi Theodoroi there are two later additions. The eastern one is a one-storied dome-shaped dome with a burial probably of destination. The west is an elongated vaulted room. The roof of both buildings had been long gone. For their formation as a museum space they were housed with a single-sided wooden roof, flooring of clay slabs, sealing work was done and a new wooden door was installed.