Today, only the remains of ancient structures, like medieval stone fortresses, strong defensive walls, and secret underground mazes, can tell you how important the city was in the past. As a rule, historians understand the time of the city foundation by its walls: previously, the construction of a new settlement was always accompanied by the construction of high defensive walls to protect against enemies.

The ancient cities of the Balkan countries have many well-preserved ancient monuments. The most ancient of modern Bulgaria is the beautiful city of Nessebar, the main treasure of which is its powerful fortress walls.

Built in the 5th century, the city's defensive fortifications were unique. Their remains still look very impressive. A fragment of the ancient wall, about 100 meters long and up to 8 meters high, is a popular tourist attraction, restored in the 19th century. The original mixed masonry made it possible to date the wall to the period of the Byzantine Empire and to establish more than 5 major reconstructions, starting from the 7th century.

The so-called Western Fortress Wall is interrupted only by a gate with two pentagonal towers. This gate served as the central entrance to the territory of ancient Nessebar. The Southern and Northern walls descend into the sea depths. In the distant past, they served as berths for the ships of the two city piers. But a severe flood sank them, along with all the other ruins of the city's defense system.

Today, the Western Fortress Wall is considered an open-air archaeological museum, and the gate leads to the Old Town with outstanding architectural monuments ranging from the time of the ancient Thracians to the late Middle Ages. Special attention should be paid to temples and churches with luxurious interior decoration and impressive exterior, with original picturesque frescoes and old hand-painted icons by talented Bulgarian masters.