ARCHAEOLOGICAL EXPLORATIONS IN PLISKA (Yanko Dimitrov – yanko_aim@mail.bg, Hristina Stoyanova) Four trenches (2, 2А, 3, 3А) were carried out, in order to trace out the ditch of the timber wall explored in the previous archaeological seasons. Two rectangular places for stirring mortar, constructed of fragmentary and intact bricks, were discovered in trenches 2 and 3. They are parallel to the eastern fortification wall and are situated at 1.05 – 1.16 m from it. A second row of rectangular places for stirring mortar, constructed of fragmentary tiles, was discovered in trench 2A, under a layer of fragmentary tiles. Another 3 m from the wall, a foundation constructed of bricks and clay, was explored in trench 2, while only the layout of the foundation was registered in trench 3. The construction dates to the end of the 9th – first half of the 10th centuries AD. A pavement of intact and fragmentary bricks was explored to the east of the wall foundation layout in trench 3. A timber construction was traced out at 1.50 m in depth in trenches 2A and 3A. During the previous archaeological seasons, a ditch with a timber wall oriented north – south was registered running trough trenches 4A, 5A, 6A and 7A. Two rows of pits were explored to the east of the ditch. The wooden constructions had two stages of building. According to the pottery, the constructions date to the end of the 8th – beginning of the 9th centuries AD. Probably, the constructions are parts of buildings dug into the ground and situated to the east of the southeastern corner of the earlier timber fortification of the residence of the proto-Bulgarian khan.