This former collegiate church, which was once part of the diocese of Orihuela, was built in the 17C on the site of an old mosque. In 1959, it received from Pope John XXIII the title of co-cathedral and became the seat of the bishopric of Orihuela-Alicante. The soberly proportioned nave, a typical example of Juan de Herrera's classicist style, is crowned by a 45m-high cupola.