Duomo di San Martino
Romanesque cathedral dating to 14th century. Contains the must-see Volto Santo and Ilaria del Carretto's Sarcophagus Note you have to pay to see this - By Jacopo della Quercia. Includes a sculpture of the crucifixion attributed to an eyewitness, Nicodemus. Some interesting carvings in the marble exterior, including a labyrinth.
To be found off the via fillungo, main entrance by piazza scarpellini. the remains of the amphitheater are gone. the houses there are of medieval origin, built where the spectator stands were. the amphitheatre hosts concerts and many international performers including van morrison and the eagles have played here.