Basilica of San Petronio

How to visit without overpaying

San Petronio fills the south side of Piazza Maggiore, and its half-finished facade — marble at the bottom, bare brick above — is the first thing most people photograph in Bologna. The good news is that walking into the nave is free. This is one of the largest brick Gothic churches anywhere, and you can stand under its vaults, see Giovanni da Modena’s fresco cycle and the side chapels, and leave without spending a euro. The small museum off the nave is free too.

The only paid bit is a single €5 chapel ticket (about £4.30, or €3 reduced, under-10s free), bought inside with no booking. It covers three side chapels, but the one to see is the Bolognini Chapel of the Magi: it’s worth the few euros for a close look at the 1410s fresco of heaven and hell — the lurid Inferno panel is the one the guidebooks talk about. Skip it if you’re short on time; the rest of the church gives you the scale and the atmosphere for nothing. Note the opening hours split the day: 08:30 to 13:30, then a long lunch closure, reopening 15:00 to 18:30 (the chapels keep slightly tighter hours, 09:00–13:00 and 15:00–18:00). Dress to cover shoulders and knees, and take your hat off at the door.

The meridian line, and is it worth it?

Find the brass strip running across the floor of the left aisle: that’s Cassini’s meridian line, laid in 1655 and for a long time the world’s longest indoor sundial. A pinhole high in the vault drops a disc of sunlight onto it, and around solar noon on a clear day the spot crosses the line — time your visit for late morning if you want to catch it. It’s free, easy to miss, and the most genuinely unusual thing in the building.

San Petronio earns its 30 to 45 minutes precisely because it asks nothing of you. Don’t plan your day around the panoramic terrace — it shut permanently after restoration, so the rooftop view that older guides mention is gone. For a view over the rooftops, walk five minutes to the Asinelli Tower and climb that instead, then come back to the piazza for an aperitivo.