UNDERWATER ARCHAEOLOGICAL EXPEDITION NEAR THE TOWN OF KAVARNA (Asen Salkin – darina_mircheva@abv.bg, Penko Georgiev) Remains of a sunken quarter of Roman Bizone were discovered during the underwater archaeological explorations in the harbor of Kavarna. A collapse of numerous stone blocks was located in the harbor, at 6 m under the sea level. A marble male head from the Roman period and a base of a column were found during the previous underwater explorations. A well-preserved ancient millstone, an axle of a stone door, parts of a wall built of bricks, a profiled quadrilateral block with an opening in the middle and grooves on its sides, and numerous fragments of dolia were discovered during the present explorations. Presumably, a large administrative building, storehouses or a harbor construction (a wall of a quay) existed on that place during the Roman period. Similar transgressive and regressive processes from the 1st century BC to the 2nd century AD were registered on the coast of North Dobrudzha in modern Romania. An active movement of the land in that part of the Black Sea coast happened in that period.

UNDERWATER ARCHAEOLOGICAL EXPEDITION NEAR THE TOWN OF KAVARNA (Asen Salkin – darina_mircheva@abv.bg, Penko Georgiev) The explorations of the sunken part of the Roman period Bizone that is located in the gulf of Port Kavarna continued. Piles of stones and several dozens ashlars were found. One ashlar has a hole in its center and grooves. A millstone, an axle of a stone door, a marble head of a statue of the Roman period, two bronze dishes, animal bones and local pottery that were found until the present moment testify to the existence of buildings and the active settlement life. The numerous sherds of dolia may show that storehouses for grain existed there. There is a pile of ashlars in front of the sunken part of Bizone and most likely, there was a wall of a quay used for lading and unloading merchandize constructed on that place. A stone post for mooring the ships alongside the quay was also found.

UNDERWATER ARCHAEOLOGICAL EXPLORATIONS AT BIZONE (Nayden Prahov – naydenprahov@yahoo.com, Asen Salkin) The underwater explorations were carried out in front of Cape Chirakman, in the harbor and to northeast of the eastern breakwater, from c. 2 m to c. 10 m below the sea level. A geophysical survey was carried out with a multibeam echo sounder and side-scanning sonar. A detailed bathymetric 3D model and bathymetric maps were produced. An aerial orthophoto shooting was carried out with a drone and a detailed photogrammetric terrain model of the land and adjacent water area was produced. Diving surveys were carried out. In 1961, a wall in _opus mixtum_ was discovered at c. 150 m in front of Cape Chirakman, but in 2020 it was not found. Diving surveys were also carried out in the western part of the small bay between the middle and the eastern breakwaters. During previous underwater explorations, architectural fragments, a head of a marble statue, two bronze trays, sherds, a coin, etc. were discovered there. In 2020, a column drum and dozens of ashlars were discovered, some of them with grooves to accommodate iron clamps. The concentration of these architectural remains indicated the existence of destroyed monumental buildings. In 1969 and 1971, an ancient breakwater was explored in the eastern part of Kavarna Bay; it started 150 m from the shore and was 120 m long. In 2020, the remains of the breakwater were not discovered.