EXPLORATIONS IN AHTOPOL (Tsonya Drazheva – archeo@burgasmuseums.bg) The Late Antique and Mediaeval fortress is located on a peninsula, 0.5 – 0.6 ha in size. Rescue excavations on a building plot, 26 m by 9.40 m in size, were carried out. Part of the fortification wall, 26 m in length and preserved up to 2.50 in height, was discovered. The wall was built in opus mixtum, with faces of ashlars bonded with mortar and emplectum. Part of the lower band of bricks is preserved at 2.05 m above the foundation. Bands of four rows of bricks are preserved in the collapsed parts of the wall. The fortification wall is 3.40 m in width and is additionally reinforced with a wall adjacent to its outer face. The reinforcement of the wall was in the same building technique: ashlars bonded with mortar and emplectum adjacent to the older wall. The coins of Theodosius I and Justinian I found during the exploration and the building technique date the construction of the fortification wall to the end of the 4th – middle of the 5th century AD. Disturbed cultural layers were explored from the inner side of the wall, down to 2.35 m in depth. They contain red-gloss pottery of the Roman period, Early Byzantine pottery, sgraffito pottery of the 12th – 14th centuries, Late Mediaeval glazed pottery of the 16th – 17th centuries, etc. A well, 4.20 m in depth, built of ashlars bonded with mortar, was explored at the foundations of the fortification wall, from its inner side. The well is synchronous to the wall but around the mid 14th century it stopped functioning and began to be used as a garbage pit. Sherds of the 16th – 17th centuries, animal bones with traces of food waste, seeds, etc. were found within the well.