Basilica di San Petronio, Bologna

The 15th largest church in the world, Basilica di San Petronio is the main place of worship of Bologna. The basilica has been home to the sacred relics of its namesake since 2000, but its claim to fame is its history of sacred instrumental and choral music. Two grand organs installed in 1476 and 1596 often fill the main chapel with music. In the 17th century, astronomer Giovanni Domenico Cassini designed a sundial that's in the paved ground outside the basilica on the left. At 66.8 m (219 ft), it is the longest sundial in the world. Use our Bologna sightseeing planner to visit Basilica di San Petronio on your trip to Bologna, and learn what else travelers and our writers recommend seeing nearby.