Alghero was erected by the Doria family of Genoa about 9 centuries ago, in 1102, on a peninsula several hectares wide. The choice of the place was not accidental: impregnable from the sea thanks to the high walls still visible today and the treacherous seabed that did not allow even medium-sized vessels to approach within cannon range, and admirably fortified on several occasions in both the land and sea parts, also as a result of the expansion that made it necessary to enlarge the spaces protected by the walls.
In order to further secure the fortress-city, a huge canal was dug that turned the peninsula into an island, connecting the sea in the harbor with the sea in front of the Esperò Reial tower. The canal was crossed by a road (today's Via Vittorio Emanuele) that reached as far as the Porta a Terra, where the only entrance on the landward side opened, accessible only by a drawbridge. Alghero was and is a city of incredible charm, the ideal place for those who love the typical lines of the architecture of the past, here strongly influenced by the Catalan-Aragonese domination.
Under the Crown of Aragon Alghero experienced its greatest development as a fortress-city: the deep ties of yesteryear are still evident today in the local dialect, a remnant of what for centuries was the only official language: Catalan.