Hotels near Basilica di San Petronio

The Basilica di San Petronio (Piazza Maggiore 3) is the largest Gothic church in Italy by volume that was never completed - its facade is half marble and half bare brick, the marble cladding never applied above the middle tier because funds ran out in the 17th century. The interior is 132 metres long and 66 metres wide, with 22 side chapels containing some of the finest medieval and Renaissance art in Emilia-Romagna. In the left nave, an extraordinary meridiana line (a 17th-century solar observatory designed by Giovanni Domenico Cassini) crosses the floor - at solar noon, a beam of light through a hole in the facade traces the date.

Entry to the basilica is free. The small museum attached to it (side entrance) covers the building's construction history and holds terracotta models of the never-completed sections - entry 3 EUR.

Pro Tip: Visit at solar noon (approximately 1:10 PM local time in summer) to see the meridiana in action - the pin-hole beam of light tracks across the 67-metre marble line on the floor, precise enough to determine the date to within a day. Stand near the line from 12:50 PM and watch it cross.