The Diocesan Museum of Sacred Art, housed in the former Church of the Rosary, displays the liturgical treasure of Alghero Cathedral and the city’s historic churches (16th-19th centuries). The church derives from a medieval civil construction, evidence of which can be seen in the two dichromatic ashlar blind portals located on the left side of the facade. When Catalan rule took over, the factory was expanded and became the home of a patrician family. Also visible on the left flank are some Gothic single and double lancet windows, while two sandstone ashlar portals appear on the facade. The Diocesan Museum of Sacred Art exhibits several simulacra of saints bearing witness to the cults and devotions that, over the centuries, have nurtured the faith of the people of Alghero, including the gilded statue of Our Lady of the Seafarers (15th century) and a St. Michael the Archangel from the late 17th century. The cycle of paintings depicting the life of Christ and the Virgin, to be ascribed to a 17th-century Genoese school, is significant.