ARCHAEOLOGICAL EXPLORATION OF PUBLIC BUILDING IN DEULTUM (Hristo Preshlenov – hristo.preshlenov@abv.bg) An occupation level, 0.75 – 1.40 m in thickness and dating to the 4th – 7th centuries, was explored in a sondage of 100 sq. m, situated to the west of the commercial premises excavated in 1991–1992. The level was formed because of the inhabitation of monumental late antique buildings, which were reconstructed several times, some of them being with presumable farming functions, and other ramshackle early mediaeval dwellings. These constructions covered the area of a late Roman decumanus, already not in function, and its adjoining buildings. In the southwestern quarter of the sondage, a clay layer levels some archaeological structures set on fire before the end of the 330s AD. The placing of the layer was related to the inhabitation of a monumental building. During two later occupation periods its floor level was raised and the entrance was partly blocked from the inside with re-used bricks, while being narrowed from the west. The superstructure of the building is constructed of masonry in horizontal courses. The wall has outer faces made of roughly hewn blocks and a core of small broken stones and bricks bonded with mortar. Another wall made of broken stones bonded with mortar and leveling courses of bricks, coming from an earlier period, was discovered in the southwestern quarter of the sondage. After the beginning of the 4th century AD, it was transformed into a western wall of the building. The southeastern corner of another monumental building was found in the northwestern quarter of the sondage. It was built of broken stones and re-used big ashlars bonded with mortar. The latest occupation remains in this part of the late antique town date to the beginning of the 7th century.