ARCHAEOLOGICAL EXPLORATIONS IN PLISKA (Yanko Dimitrov – yanko_aim@mail.bg, Stanislav Ivanov) About 250 sq. m in the Fortified Palace (the Citadel) were explored. The Southern Sector covered the interior of Room G of the building with parallel rooms arranged in a line, situated near the Large Cistern. The Northern Sector covered the northwestern part of the Citadel between Building B4 and the Large Cistern, to the south of the Palatial Church. A sector, 3.60 m long, of the main early water-conduit were explored. It was constructed of terracotta pipes placed over a mortar foundation and covered with a ridge roof of bricks. A sector, 5 m long, of another similar later water conduit was explored. A sector, 3.50 m long, of a third water-conduit of terracotta pipes was discovered. A sector, 8.80 m long, of a drain of terracotta pipes placed in a trench was explored. There were incised drawings of ploughs on two of the pipes. Sectors of 10 foundation trenches of overlapping timber fences of different periods were explored. A brick with incised drawing of a horseman and a bird, which was used as a foundation pad in a trench, was found. Part of a foundation trench of a circular timber building was explored. The trench was 1 – 1.10 m wide and 1.10 – 1.20 m deep. Eight post-holes were discovered. Most of the vertical timber beams were quadrilateral with section 25 to 50 cm. The building was 11 – 12 m in diameter. This was the fifth circular building discovered inside the Citadel. Postholes of different timber buildings were found. A sector, 18 – 20 m long, of the underground secret wide passage were explored. The passage had two periods of existence. A pavement of bricks was documented. Two rows of bricks, placed in a trench along the walls of the passage, were discovered. The bricks served as a foundation for the timber planks and beams which supported the roof of the passage. Sherds and a bone pincushion were found inside the underground passage. All of the constructions discovered date to the 8th – 9th centuries AD.