Dubrovnik’s limestone walls, which run uninterrupted for 1.2 miles around the city, are among the best preserved in the world. The first fortifications were built already in the 8th century (the fact that the city was able to resist 15-month besiegement in the 9th century means that it was fortified well). When the sea channel separating the city from the mainland was filled with earth in the 11th century, the city merged with the settlement on land and soon a single wall was built around the area of the present-day city core. The whole city was enclosed in the 13th century, except for the Dominican monastery, which came under the walls’ protection in the 14th century. The most intense construction of the walls took place from the mid-15th to the end of the 16th century.
The ramparts are 72 feet high in places, and from 13-19 feet thick on the landward side and from 3-9 feet thick on the sea side. In front of the main wall on the mainland side is an outer wall, in front of which used to be a moat.
Minčeta Fortress is to the north; the port is protected by the detached Fort Revelin in the east and St. John’s Fortress in the southeast. The western entrance to the city is protected by Bokar Tower. Fort Lovrijenac also protects the western end of the city from danger from the sea and land. In addition to these fortifications, the city walls are protected by two round towers, 12 quadrilateral forts, five bastions, and two corner towers, while the scarp wall is flanked by one large and nine small semicircular bastions.