This massive Romanesque church, also known as the Cathedral of San Vigilio, forms the southern edge of the Piazza del Duomo. Locals refer to this square as the city's salotto (sitting room), as in fine weather it's always filled with students and residents drinking coffee, sipping an aperitif, or reading the newspaper. The baroque Fontana del Nettuno presides over it all. When skies are clear, pause here to savor the view of the mountaintops enveloping the city.
Within the Duomo, unusual arcaded stone stairways border the austere nave. Ahead is the baldacchino (altar canopy), a copy of Bernini's masterpiece in St. Peter's in Rome. To the left of the altar is a mournful 16th-century crucifixion, flanked by the Virgin Mary and John the Apostle. This crucifix, by German artist Sisto Frey, was a focal point of the Council of Trent: each decree agreed on during the two decades of deliberations was solemnly read out in front of it. Stairs on the left side of the altar lead down to the 4th-century Paleo-Christian burial vault. Outside, walk around to the back of the cathedral to see an exquisite display of 14th-century stonemason's art, from the small porch to the intriguing knotted columns on the graceful apse.