ARCHAEOLOGICAL EXPLORATIONS IN THE MARKELI FORTRESS (Zhivko Aladzhov, Dimcho Momchilov – karnobat.muzey@mail.bg, Rositsa Hristova) The southern fortification wall was discovered up to the bastion, which was preserved up to 3.25 m in height and measured 3 m by 3.20 m. The interior of the southeastern corner tower measured 4.10 m by 4.45 m with walls 2.10 – 2.80 m wide, preserved up to 2.70 m in height. The entrance of the tower was 2.05 – 2.35 m wide. The interior of the southeastern corner tower and the three towers along the eastern fortification wall had a cross-like layout. The towers and the eastern fortification wall were built in opus mixtum. Early Byzantine debris and proto-Bulgarian pottery were found on the floor of the southeastern corner tower. Material of the 11th – 13th centuries was found in the upper stratum. The explorations of the eastern fortification wall 3.10 m wide continued between both corner towers. A place for stirring mortar dated after the 11th century and three consecutive floor levels were discovered in Tower No. 18. A Byzantine seal of the 11th century was found, showing St. Mary Oranta with Christ and an unidentified Saint. The northeastern corner tower measured 5/7.90 m by 9 m. A staircase was discovered from the southern side of the tower, probably related with farm rooms of the 11th – 13th centuries, situated in front of the eastern fortification wall. The finds from the excavations included a medallion, an Early Byzantine coin, a Byzantine scyphate coin, a seal, two iron picks, small knives, awls, querns, whetstones and a stone mould. The Early Byzantine fortress was destroyed by the proto-Bulgars. During the 11th – beginning of the 13th centuries the fortress was not functional and Markeli was an unfortified town within the Byzantine Empire.