Just inside Porta a Mare, Piazza Civica is Alghero’s showcase square. In a former life it was the administrative heart of the medieval city, but where Spanish aristocrats once met to debate affairs of empire, tourists now converge to browse jewellery displays in elegant shop windows, eat gelati and drink at the city’s grandest cafe – Caffè Costantino. It occupies the ground floor of the Gothic Palazzo d’Albis, where the Spanish emperor Charles V famously stayed in 1541.