Da castello a castello, il problema della difesa della costa ionica: i casi delle fortificazioni di Catania e Aci Castello

Because of its centrality in the Mediterranean Sea, Sicily has always been a territory of flows, and a crossroads of exchanges, which made it necessary to control the coast. In the history, the side most exposed to the flows coming from the Middle East and North Africa, was the south side, with the two coasts of the Sicilian channel and the Ionian side. Of the two coasts the second, for different reasons, including the largest number of inhabited sites and therefore the greatest anthropic concentration, has posed the problem of defense, the testimony is given by the largest number of fortifications. The problem of defense, already arisen in the Hellenic period, and renewed on the occasion of the Islamic expansion, assumes strategic value with the Norman and Federician castles, and again with subsequent dominations. The research in progress, which is briefly outlined below, deals with the problem of reconnaissance in the Swabian period, and that of the Spanish crown between the fifteenth and sixteenth centuries, with the production of military maps, focusing the general attention on the ionic tract. As a case study, the attention is placed on the castle of the city of Catania and the stronghold of Aci Castello. The research with the tools of drawing and representation analyzes the ancient maps of the territory and the city, to interpret the relationship between the fortifications and the territory. So starting from the surveys carried out with direct methodology, photogrammetric, digital and laser scanner, addresses the two case studies, different in their strategic intentions.