From defensive system to urban space. A century of transformations of the “Castle” of Cagliari

The fortifications of the ancient area of Castello (castle), in Cagliari, are built continuously from XIII century to XVIII, and are structured according to the defensive typologies of the different periods. Starting from the early years of the XX century, the military use ceases and it starts a constant transformation in civil uses. Some of the bastions are reused as public spaces (square, promenade, athletic field) and others are subjected to deep architectural transformations in order to host cultural functions (university, museum, schools). Common destiny of many European cities, Cagliari differs because, thanks to its orographic conformation that forces walls and bastions to overtake differences in height of about 20-30 metres, fortifications are not demolished but used as areas for new architectures. In some cases, as we will present in the paper, they are architectures of great quality, which establish new and interesting connections with the fortifications themselves, enhancing the overall quality of the old town.