DIOCLETIANOPOLIS (Mitko Madzharov – m_madjarov@abv.bg, Dimitrinka Tancheva) The explorations of Room No. 05 situated to the north of the second caldarium continued. The wall between Room No. 05 and the tepidarium showed the two construction phases of the thermae. The building features in both construction phases were identical, which indicated that the extension of the thremae to the east occurred soon after the initial construction of the architectural complex. A layer was explored, containing bricks and sherds of the 4th – 6th centuries AD. The eastern wall of Room No. 05 was discovered. The wall had a vaulted niche, subsequently closed by the wall of the later tepidarium. During the first construction phase, the niche probably was a window. A second larger vaulted niche with a marble edge at its bottom, dated to the first construction phase, was discovered in the northern part of the wall. A midden pit was discovered dug out into the Late Antique stratum, containing animal bones and sherds of the 9th – 10th centuries AD.