Metropolitan Cathedral of S. Maria de Episcopio: it is only right to call the church by its formal title, if the ancient importance of the church, founded in the seventh century but rebuilt in the ninth and again in the twelfth, is to be matched by due solemnity of words.

The Second World War with its bombing caused almost complete destruction, leaving only the still beautiful Pisan-style façade on Corso Garibaldi to survive but for post-war reconstruction, with inscribed Longobard funerary inscriptions removed from the sarcophagi that were in the atrium demolished by the bombs. Beneath the church floor, one can visit the archaeological section of the Diocesan Museum, the result of excavations made possible by the reconstruction, with frankly previously unimaginable discoveries from the Samnite and ancient Roman ages, and glimpses even further back in time to the Neolithic period. The actual museum holdings include groups of fragments of sepulchral charms, pieces of Lombard frescoes and the wrought-iron St. Beard's Chair, all from the 9th century, as well as a 14th-century fresco of Our Lady of Mercy and silverware and textiles from the Treasury.

The bell tower of the cathedral dates back to the late 13th century. At the bottom of the outer right side of the church, the so-called Arch of the Sacrament is actually a Roman-era passageway, stripped of its original decoration.