The main church of the town was founded certainly before the beginning of the eleventh century on Roman ruins, probably a pagan building. In the centuries it experienced several adjustments, until the recent ruinous ones in 1905, made even worse by the repair works of 1955, after the violent bombardment in 1944. Outside the massive fourteenth-century bell-tower stands out. It is made of brick and surrounded at the top by Gothic little arches interlacing with each other. The Baroque ornaments added in 1660 were removed, so that today the church shows inside parts of its fourteenth-century Gothic structure: at Latin cross, it consists of a nave and two aisles divided by pillars and brick ogival arcades. It keeps on the high altar a stone frontal with bas-reliefs of the VII century. The thirteenth-century cross belongs to the typology with movable and detachable arms used in morality plays. The crypt dates before the eleventh-century and has pillars from a Roman building and thirteenth and fourteenth-century frescoes.