The Basilica of San Petronio anchors the southern side of Piazza Maggiore, its vast, unfinished façade a defining sight in Bologna. Pink and white marble covers the lower section, while bare brick rises above it. Dedicated to the city’s patron saint, the Gothic basilica was begun in 1390 as a civic project, expressing the ambition and independence of medieval Bologna.
Inside, lofty arches frame a spacious nave and a series of chapels filled with art. Look for the frescoes by Giovanni da Modena in the Bolognini Chapel and the carved wooden choir stalls. One of the basilica’s most intriguing features is the meridian line laid out by astronomer Giovanni Domenico Cassini in 1655: on sunny days, light enters through a small opening high in the vault and falls across the marked floor around solar noon.
San Petronio is easy to reach on foot from anywhere in Bologna’s historic centre, and it pairs naturally with a walk around Piazza Maggiore and the nearby Fountain of Neptune. General entry is usually free, though some areas may require a ticket; check current opening hours and access arrangements before visiting. Dress modestly for this active place of worship, and arrive around midday if you hope to see Cassini’s meridian at work.