When observing Alghero from the sea, beyond the port and the city walls, you will see the bell tower of Santa Maria, the religious heart of the historic centre. When the diocese of Alghero-Bosa was proclaimed (1503), the city was without a temple that could serve as a cathedral: its construction began in 1530. The works lasted for centuries, as revealed by the mixture of styles: the base is Gothic-Catalan, on the model of the Cathedral of Sant’Eulalia in Barcelona, and later interventions followed a late-Renaissance design. In 1593, the cathedral was consecrated, despite not being finished: in 1638, vaults were built over the transept and the dome.