ARCHAEOLOGICAL EXPLORATIONS OF THE MEDIAEVAL FORTRESS MARKELI NEAR THE TOWN OF KARNOBAT (Zhivko Aladzhov – aim-bas@aclubcable.com, Tsonya Drazheva, Dimcho Momchilov) The excavations allowed us to clarify the stratigraphy in the eastern end of the fortress (in the area of the Christian building complex of the 4th – 14th centuries) as well as the chronology of the town development in that part of the site. The inner face of the eastern fortifying wall, between towers Nos. 17 and 18, was uncovered in order to clarify the fortification system and its reconstruction. The foundations of the platform that supported the stairs from the northern side of tower No. 18, whose construction was related to that of the eastern fortification, were excavated. The tower dates to the second half of the 5th century AD. In addition, eight Christian burials, coming from the end of the 10th – 11th centuries, were discovered in the eastern part of the churchyard. The water supply tower near the river of Azmak was also explored. Its construction was related to an early building period of the fortress. A deep reservoir cut into the bedrock was discovered. The bottom of the reservoir lies below the river level and was related to the river by means of an overflow drain for keeping the water column within the supply tower. From its northern side, the reservoir was protected by a rectangular fortification tower with an entrance to the passage leading towards the fortress. Finally, the profile of the lower fortification rampart was cleared. Four ritual pits with burnt earthen plasters, filled with sherds and burnt animal bones, were discovered in the rampart basis. The pottery dates from the 8th to 5th centuries BC.