Southern Fortress walls

The fortress walls in the area of the modern amphitheater, located on the southern shore of the peninsula, are part of Nessebar’s complex defense system, which has undergone numerous reconstructions over the centuries. In this section, between the quadrangular tower and the entrance to the southern port, significant repair work was carried out during the reign of Emperor Theodosius II from 408 to 450 AD. On its inner side, the wall in this zone was divided into specific niches conchae, while on the outside, it was faced with precisely processed rectangular stones. Unlike the massive western wall, which reached a thickness of nearly 4 meters, the southern sector of the fortifications was thinner with a thickness between 1.70 and 2 meters. It is believed that these walls suffered serious damage during an earthquake in 480 AD, after which they were restored using a mixed construction opus mixtum consisting of alternating belts of stone and brick. A vital aspect of the fortification in this part was the protection of the southern port, where the quay walls and their towers were extended into the sea as a continuation of the fortress line to conceal the docks from the mainland. Today, a large portion of the southern side of the peninsula, especially southeast of the Church of St. John Aliturgetos, has been lost due to the process of marine transgression and rising sea levels. In the area known as "Plakamoto", located immediately next to the modern theater, large processed stone blocks are still visible beneath the waves. These ruins are a silent testament to the monumental buildings and fortifications of the past that the sea has swallowed over the centuries..