CASTRA RUBRA (Boris Borisov – bdborisov@abv.bg, Deyan Rabovyanov) A building located in mansio Castra Rubra on Via Diagonalis was discovered in Kozlari locality. The building was constructed of uneven and cut stones bonded with mortar. The walls are 75 cm wide. There are two entrances. The finds and the coins date to the 1st – 4th centuries AD. According to the coins, the fortress situated in Kaleto locality was built during Anastasius I or Justinian I. The fortress was destroyed during the invasions of Slavs and Avars. The destruction is attested by a stratum with traces of fire and a hoard of seven gold coins of Maurice and Heraclius, the latest ones minted in AD 616 – 625. Soon after, the fortress was reconstructed and existed until the military campaigns of the Bulgarian Khan Krum (AD 803 – 814) in AD 812. The destruction is attested by a stratum with traces of fire, containing coins of Nikephoros I Logothetes and Stauracius. After the destruction, a Byzantine unfortified settlement appeared on the ruins of the fortress. Seals by Byzantine strategoi (Turmarchus Synesios, etc.) of the second half of the 9th century AD were found. The fortress has a trapezoidal lay-out. The fortification walls are built in opus mixtum and are 1.95 – 2.15 m wide. The fortress has one tower-gate and four corner towers and covers an area of 0.11 ha. It has a main entrance with two two-wing doors in a rectangular tower-gate situated in the corner between the eastern and the northeastern fortification walls. The three corner towers are rectangular and are protruding from the fortification wall, while the southwestern corner tower is situated from the inner side of the wall and has a postern. The fortification wall was c. 10 m in height. Houses with rooms arranged in a line were discovered in the fortress. House No.1 was built during the first half of the 9th century AD when the fortress was already not functional. During the 11th – 12th century, a settlement appeared on the debris of the neighboring Castra Rubra. Twelve graves of the 3rd – 6th century AD and the 11th century were discovered.