Historic-artistic value is also the National Cathedral dedicated to Saint John the Baptist (St John the Baptist Cathedral), in Gothic-Romanesque style and dating from the late 14th century, in which are contained the remains of san Mauro. Inside the Cathedral a small and important painting depicting the Holy Baptist run on copper plate has been recently attributed by researcher Alex Carson to Livio Agresti Mannerist painter. In the Chapel of the Madonna del Popolo there are frescoes by Corrado Giaquinto of 1750.