The old town of Nessebur is situated on a small Black Sea peninsula, and is connected to the land via a narrow isthmus.

It was first inhabited in the Bronze Age, when the neck of land was barricaded in the event of danger. The first Thracian settlement, Messembria, was built around 2000 BC. Greek colonists settled there in the 6th century BC. The town started to decline after its seizure by a Roman garrison in 72 BC.

Later it passes under Greek rule again and becomes an important maritime base. Greek and Bulgarian rule alternated until the second Bulgarian Kingdom, when the town became an important centre of the state under tsar Ivan-Alexander (1331- 1371). Hundreds of anchors, taken out of its coastal waters, demonstrate its importance as a commercial port. Excavations have uncovered precious and exquisite objects, as well as inscriptions, sculptures and decorations which speak of the town's structure, cultural institutions and temples. Its significance hadn't dwindled during the times of Roman and Byzantine rule.

The establishment of Christianity as a state religion during the 4th century changes the town considerably. The largest early Christian church- The Old Bishopric -still survives. The churches, 41 according to some sources, were built by Bulgarians and Byzantines alike. Only a few survive- The Old Bishopric and parts of "Eleusa Mother of God" (both 6th century basilicas), St Stephan (12th century), St Todor (13th century), Pantokrator (14th century), St Ivan the Unsanctified, St John the Baptist, etc.

In 1336, the crusaders of prince Amedeus VI of Savoy invaded the town, tempted by its riches. In 1453 Nessebur falls under Turkish rule. Trade and fishing became the main occupations. The old Nessebur houses, which the town is now famous for, evolved at that time. The lower floor of a typical house is built of stone, and the second - of wood planks, with bow-window hanging above the narrow cobbled streets. Many of the buildings have now been restored and declared cultural monuments, along with the old fortress wall and gate. The latter is part of the oldest local fortress. The city has been declared a museum-town.

The Ancient City of Nessebar was included in the World Cultural and Natural Heritage List at the World Cultural and Natural Heritage Committee session of 1983 in Florence, Italy