Pope Pius IV ordered the construction of the Archiginnasio university building next door to block the Basilica's expansion, preventing it from exceeding St. Peter's Basilica.
The floor features the world's longest indoor meridian line, measuring 66.8 meters, which is still used today to calculate the astronomical timing of the solar year.
The facade's lower marble decorations were designed by Jacopo della Quercia, whose work influenced Michelangelo.
The church was originally intended to be in the shape of a Latin cross, but the project was truncated, resulting in the current proportions.
It is not technically a cathedral, as the seat of the Archbishop of Bologna is the Cathedral of San Pietro.
The Basilica has hosted several historic events, including the coronation of Emperor Charles V by Pope Clement VII in 1530.
The upper portion of the facade remains unfinished, leaving exposed the rough brickwork that served as the base for intended marble cladding.
The church was constructed using city funds rather than ecclesiastical ones, symbolizing Bologna's civic power during the Middle Ages.
Basilica di San Petronio is the largest church in Bologna and serves as a primary civic symbol dedicated to the city's patron saint. Construction began in 1390, though its facade remains famously incomplete, featuring a marble lower section and a raw brick upper portion. The interior houses 22 side chapels decorated with significant Renaissance artworks and frescoes. A unique scientific feature is the Meridian line, a brass strip inlaid in the floor created by astronomer Gian Domenico Cassini in 1655. This meridian acts as a solar observatory, marking the sun's position throughout the year through a hole in the ceiling. The building’s vast interior volume reflects its original intent to be larger than St. Peter’s Basilica in Rome, a plan ultimately thwarted by papal intervention. It remains one of the largest brick-built churches in the world by volume.
From the center of Piazza Maggiore to capture the unique contrast between the finished marble base and the raw brick upper facade.
Check the meridian line at solar noon to see the sun beam hit the brass plate in the floor.
Visit the terrace for a panoramic view of Bologna's red rooftops and surrounding hills.
Use the provided information panels inside to identify the distinct artistic styles within the 22 chapels.
Do not ignore the signage regarding photography restrictions, as flash photography is prohibited near sensitive artworks.
Shoulders and knees must be covered; remove hats upon entering; maintain silence.
