CARIA (Boyan Ivanov – b_totev@abv.bg, Dobri Dobrev, Olga Pelevina) The Late Antique quadriburgium Caria was situated on the sea shore close to the Greek colony Karon Limen founded in the 6th – 5th century BC. During the Early Byzantine period, the quadriburgium was partly reconstructed. Underwater archaeological explorations had been carried out in 1962, 1979 and 1980 and archaeological excavation of the fortress had been carried out in 1976 – 1979 and 1995 – 1996. In 2016, a sector of the northern fortification wall of the Early Byzantine fortress was discovered, 13.45 m long. The wall was 2 m wide, preserved up to 1.50 m in height. Its foundation was 1.70 m deep. A circular fortification tower was documented, 8.40 m in diameter. A rectangular tower was documented on the southern fortification wall. The western fortification wall was 46.80 m long and 1.70 – 1.90 m wide. Two sectors were explored. The wall was built of ashlars bonded with mortar in opus emplectum and opus mixtum. Five dolia were discovered in front of the northern fortification wall and three dolia in front of the southern fortification tower. A monumental wall was documented in front of the southern fortification tower, probably belonging to the earlier quadriburgium. Similar wall was also documented to the north of the circular tower on the northern fortification wall. A stratum from the Hellenistic period was explored. A pavement of stone slabs was discovered and sherds from amphorae, coins and a lead slingshot were found. Coins of Theodosius I and later emperors were found in the Late Antique stratum. The Early Byzantine fortress was destroyed by the Avars in the beginning of the 7th century AD.