Basilica of San Petronio

The Basilica of San Petronio dominates the south side of Piazza Maggiore in Bologna, Emilia-Romagna. Work began in 1390, financed by the city government, with a design attributed to Antonio di Vincenzo, intended to rival even St Peter's in Rome. The plan was never completed: papal authorities were reluctant to see a church bigger than the Vatican's, and the unfinished facade, with its lower marble and upper bare brick, is the most striking sign of that history. The nave is about 132 metres long and 60 metres wide at the transept, in a Gothic style with soaring brick piers and white plaster walls. Famous elements include the carved doorway of the main portal by Jacopo della Quercia, made between 1425 and 1438 with scenes from Genesis; the chapels of the nave, with works by Lorenzo Costa and the Bolognese painters; and the large unfinished 15th-century fresco of Heaven and Hell by Giovanni da Modena. In 1530 the basilica was the setting for the coronation of Charles V by Pope Clement VII, an event that marked the last imperial coronation by a pope. On the floor of the left aisle runs a meridian line laid out by the astronomer Giovanni Domenico Cassini in 1655; a small hole in the vault projects a sun image onto the line at midday, and the instrument was used to check calendar and astronomical measurements. The building was damaged by war and weather, and restoration work has been steady over the centuries, including the repair of facade sections, though the facade itself remains unfinished by choice. Today the basilica is a place of worship and a major monument. Entry is free, but the dress rules require shoulders and knees to be covered, and there may be a small fee for photographing or accessing the terrace on some days.