Dedicated to the Conversion of Saint Paul, it was also the city's only parish until 1954. The parish church of Saint Paul the Apostle stands in the highest part of the historic center, tracing the area where in Roman times a temple dedicated, most likely, to Hercules stood.
The layout with which it appears today dates back to the mid-18th century, as also witnessed by an epigraph that can be seen on an internal arch and which reports the year 1747, even if in all probability it refers to a restoration or a reconsecration of the building, which must have dated back at least to the late Middle Ages, perhaps used as a Palatine Chapel of the Judges of Gallura. In 1939, a further intervention modified the original structure, which was transformed from a rectangular structure, with three chapels on each side, into a church with a Latin cross plan, a transept and a dome.

In doing so the ancient one was brought down oratory of the Confraternity of the Holy Cross, Adjacent to the southern side of the parish church. In place of the oratory, which featured pointed vaults in the Catalan Gothic style, a building was erected to serve as a multipurpose hall.
At the beginning of the 1990s it was decided to re-establish the ancient church of the brotherhood, adapting that building and providing it with a bell gable. 

Inside the church of San Paolo shows some very valuable art objects, such as the choir and the pulpit in wood from the eighteenth century. Among the sacred silverware kept in the sacristy, the sandals and the’silver halo of the Assumption, which appear to be the work of an unknown Sardinian craftsman of the seventeenth century, and an elegant eighteenth-century monstrance originally from Palermo.