EXPLORATIONS OF LATE ROMAN THERMAE IN DIOCLETIANOPOLIS (Mitko Madzharov – m_madjarov@abv.bg, Dimitrinka Tancheva) The exploration of room No. 01 located to the south of room No. 1 of the thermae of Diocletianopolis continued. Room No. 01 was additionally constructed adjoining the main building. Room No. 01 is built in opus mixtum and two masonry piers were discovered in the eastern part of its southern wall. The space between the piers is 1.85 m and was additionally closed with a wall. The southern wall initially had open spaces but later it was closed. The floor of room No. 01 was discovered. It consists of stones covered with mortar and bricks that were arranged on the mortar. A terracotta water-conduit inclined from the east to the west was discovered close to the outer face of the southern wall of the thermae. A vaulted passage was explored in the southern wall of room No. 1. The terracotta water-conduit reached the passage. The passage is 90 cm in height and 55 cm in width. Its walls were built of stones and the vault was constructed of bricks bonded with mortar. The floor of the passage inclines from the north to the south. The passage and the terracotta water-conduit were used to supply the thermae with cold water. The water-conduit passed alongside the cardo maximus and through by a junction-shaft it diverted towards the thermal mineral spring where the balneotherapy establishment of Diocletianopolis was built. Most likely, a mineral pool was constructed in room No. 1. The construction features of the room and the water-conduit for cold water, which cooled down the hot mineral water in the pool, support such a hypothesis.