The religious heart of the medieval city, Piazza San Lorenzo is home to two of Viterbo's finest buildings. On the southern flank is the Cattedrale di San Lorenzo , the city's handsome 12th-century cathedral, which was originally built to a simple Romanesque design but owes its current Gothic look to a 14th-century makeover. To the north, the Palazzo dei Papi served as the main papal residence from 1257 to 1281. Head up the stairs to the graceful Gothic loggia (colonnade) to peer into the Sala del Conclave , the hall where five popes were elected.
