Architectural-historical reserve "the Old Nessebar is located in the Old town, on the Peninsula, the width of which is 350 meters and the length does not exceed 850 meters. This area of Nessebar – architectural-historical reserve national scale. In addition, the Old Nessebar was included by UNESCO in their world heritage site.

The story of one of the oldest European towns – Nessebar – covering more than three millennia. In ancient times it was called Mesembria, and in the middle Ages – Messembria. Numerous archeological finds indicate a long rich history of these territories, as part of the exhibits today exhibited in the municipal Archaeological Museum.

Since its founding, the town has always been surrounded by walls, traces of which can be observed today. The first walls were built by the Thracians in the eighth century BC, and in Vстолетии Greek colonizers to their fortifications. Of the buildings of this period are most interesting fortress wall at the city gates, and another, built in the early Byzantine era, is located on the southwest shore.

Since the adoption of Christianity and the transfer of the capital by the Romans in Constantinople, then Messembria were being built Christian churches. The Church Of St. Stephen, Dating from the period from the XI to the XIII century, it is also known as "the New metropolis", as moved all the office of the head of the diocese.

Also worth mentioning other churches-museums, such as the Church of St. Saviour 1609, Church of St. Paraskeva XIII-XIV centuries, the Cathedral of Christ the Pantocrator of the XIII-XIV centuries and the Church of St. John, founded in the XIV century.

In the Old town you can visit the ruins of the early Byzantine baths, which were built in the period from VI to VIII century, and were later converted into housing and business needs.

On the reserve, in addition to the Archaeological Museum, there is the Ethnographic Museum, the exhibits of which are exhibited in the family mansion of Mosconi. The Museum's collection are craft and life of residents of Nessebar, as well as their national costumes.