SOSTRA (Ivan Hristov – ivchristov70@abv.bg) The explorations in Mansio Sostra continued. It was situated at 200 m to the northeast of Castellum Sostra. The praetorium dated to the 2nd – 3rd centuries AD and consisted of c. 12 rooms. Room E was 30 sq. m in size. Its walls were 60 cm wide, built of roughly-cut stones bonded with mortar. Suspensura 23 cm thick was discovered and a hypocaust beneath with terracotta pillae, 62 – 70 cm high and 20 cm in diameter, was explored. The room had an entrance on the southern wall, 1.39 m wide; it was walled in the middle of the 3rd century AD or later. An opening towards a furnace was discovered on the eastern wall of Room E. The finds included coins of the middle of the 2nd century AD, sherds from local red-gloss pottery of AD 150 – 250, a roof-tile with a stamp that reads: COH, but without numerals identifying the cohort and probably, it referred to Cohors II Mattiacorum. A layer of collapsed roof-tiles and burned wooden beams was discovered between the pool and the praefurnium and Rooms E and D; coins of AD 150 – 200 were found beneath. Room F (praefurnium) 8 m by 4 m in size was explored. The openings for the furnaces towards the hypocaust in the neighboring Room I were documented in the southwestern and the southeastern corners of the praefurnium. Nine rows of pillae of rectangular bricks, circular bricks and circular terracotta pipes from the hypocaust were discovered in Room I. The average distance between the pillae was 33 cm. The suspended floor was c. 35 cm thick. A small pool was discovered in Sector C, situated close to the large pool in the figidarium.