ARCHAEOLOGICAL EXPLORATIONS IN PLISKA (Yanko Dimitrov – yanko_aim@mail.bg, Mariela Inkova) The site is situated to the west of the northern pentagonal tower of the western fortification wall. It was discovered that in 1989 the excavation for the water-conduit had cut through the foundation of a fortification wall oriented northeast – southwest in the direction of tumulus No. 34. A trench was carried out and a 5 m length of the wall was discovered. Remains of mud-bricks were found above a foundation of fragmentary mortar, uneven stones and fragments of bricks. The fortification wall in that sector lies over a ditch, which is oriented east – west. The ditch runs towards a fosse, which is parallel to the wall and is situated from its western side. The fosse and the wall are probably not synchronous. Six sondages were carried out and the layout of the fortification wall was traced at 120 m in southern direction. In sondage 14 the foundation of the fortification wall lies over a construction, which probably was a house partly dug into the ground. Pottery of the 10th century AD was found in the construction.