the interior has a basilica plan with an apse and two aisles, divided by cylindrical columns and cruciform pilasters which end in complex composite capitals. next to the entrance door, under the 14th century triptych of the "madonna enthroned with child and saints", is a roman sarcophagus from the 4th century. on the right of the counter-façade is a series of panels in soft stone, dating from the high middle ages or, according to some sources, to the 12th-13th century. over the panels are frescoes of the crucifixion, of the 14th century, and the legend of saint julian, of the 15th century.