Sitting alongside the duomo, this former bishop's residence dates from the 11th century. It now houses one of Italy's most important ecclesiastical collections, with enormous documentary paintings of the Council of Trent, along with Flemish tapestries, illustrated manuscripts, vestments, and some particularly opulent reliquaries. Admission price includes entry to the paleo-Christian archaeological area beneath the duomo. A ground-floor gallery also hosts temporary contemporary art exhibitions.