Spoleto's Romanesque basilica, listed as a Unesco World Heritage Site as part of the 'Longobards in Italy, Places of the Power (568-774 AD)' group, dates from the 4th or 5th century. Unfortunately, it was off limits at the time of research after suffering damage in the August 2016 earthquake. You can, however, look inside through the main doorway, which is opened during the day.