Quite apart from their particular importance in the development of the town, the defense works, the supreme examples of which are the Old and New Fortresses, are in themselves notable examples of the military defensive art and building techniques of their time (from the 15th to the 18th c.). Built by eminent architects and engineers, they are amongst the finest examples of defensive complexes built in the Mediterranean, their effectiveness well demonstrated by the many occasions on which they withstood Turkish attack.
To construct them, human ingenuity was exploited to its maximum through art and science, in an organized endeavour on the part of the “mighty and beautiful” to predominate over nature. Mountains were levelled, harbours dredged, islands created, fortification walls and fortresses erected, and the art of the builder triumphed. As the Venetian senator Nicolo Zeno said, ”The place is exceedingly strong naturally; we have used our art and financial resources to make it impregnable.