With its black-and-white bell tower, Viterbo's 12th-century cathedral looms over Piazza San Lorenzo, the religious nerve centre of the medieval city. Originally built to a simple Romanesque design, it owes its current Gothic look to a 14th-century makeover and a partial post-WWII reconstruction.
Inside, look out for Redentore e Santi (1472) by Gerolamo da Cremona and the tomb of Pope Giovanni XXI (r 1276–77). A second pope, Alessandro IV (r 1254–61), is also buried in the cathedral, but the location of his body is a long-standing mystery.
Many of the cathedral's art treasures are today housed in the adjacent Museo Colle del Duomo.
The cathedral is free to enter but certain areas can only be accessed with a ticket (adult/reduced €9/7); this also covers admission to the Museo Colle and Palazzo dei Papi.