ARCHAEOLOGICAL EXPLORATIONS IN DIOCLETIANOPOLIS (Mitko Madzharov – m_madjarov@abv.bg, Dimitrinka Tancheva) A residence, an amphitheater and thermae are situated in the central part of Diocletianopolis. The explorations of the thermae began in 1935. They cover an area of c. 0.35 ha. An extension of the thermae to the south was documented during the archaeological excavations in 2006. The walls are preserved up to 1.70 m in height. The southern wall is 1.08 m wide and the western wall is 80 cm wide. The walls are constructed in opus mixtum with each level consisting of four courses of bricks. The bricks measure 35 cm by 35 cm by 5 cm. Three vents in the walls were documented. Two rooms and a corridor, 2.45 m in width, were discovered. Drainage was explored. Its walls are built of stones and the bottom is paved with bricks. The drainage is 52 cm wide. An air duct from a hypocaust, 35 cm in width, was discovered in front of the southern façade of room No. 1. It is constructed of stones plastered with mortar and its bottom is paved with bricks. The finds include Late Antique pottery, bronze coins of the 4th century AD, marble fragments from wall cladding and a fragment from a marble votive relief of the Nymphs.