The basilica dedicated to St. Helen, built in the 12th century, was modified over the centuries by local masters and decorated with wall paintings. The 1780 expansion gave it its present form. The interior features a Latin-cross nave with three side chapels on each side, including the Rosary and Blessed Sacrament chapels. A beautiful structure rich in marble furnishings, such as the baptismal font, pulpit, and high altar in the Baroque style, and 18th-century wooden furnishings, including the sculpture of St. Helena and the Rosary and Sacred Heart altars. The Sacristy preserves the marble basin, wooden vestment, and numerous paintings on canvas dated between the 17th and 19th centuries. Many paintings of obvious merit and value both historically and artistically. In 2007, Pope Benedict XVI elevated it to the title of Basilica. After the facade was restored in 2011, a new tabernacle was placed in the Blessed Sacrament Chapel, made of polychrome marble from the high altar of Cagliari Cathedral.
