Basilica di San Petronio (San Petronio Basilica), Bologna (must see)

Dominating the southern side of Main Square, the Basilica of Saint Petronius is Bologna’s principal church and one of the largest Gothic basilicas in the world. Dedicated to Saint Petronius, the city’s fifth-century bishop and patron saint, the basilica was begun in 1390.

The original plans were extraordinarily ambitious. The basilica was intended to surpass even Saint Peter’s Basilica in Rome in size and become one of Christianity’s greatest churches. However, the project was halted after opposition from the papacy, particularly under Pope Pius IV, who redirected resources toward the creation of the nearby Archiginnasio. As a result, the façade was never completed. Its lower section is decorated with pink Verona marble panels, while the upper portion remains unfinished brick.

Before entering, stop right in the middle of the main facade to admire the central entrance. Masterfully sculpted between 1425 and 1438, it features highly expressive reliefs from the Bible, displaying detailed Old Testament scenes vertically flanking the doorway on the surrounding side pilasters, and New Testament stories detailed on the architrave directly above the entrance. These vivid carvings were heavily admired by Michelangelo, who later drew direct design inspiration from their raw musculature for his Sistine Chapel ceiling panels. Above the door frame, the top lunette depicts the Madonna and Child standing between Saint Petronius and Saint Ambrose.

Inside, the vast, airy Gothic interior contains 22 deep side chapels. As you enter the basilica, walk down the left aisle to the fourth bay on your left to locate the Bolognini Chapel, which houses Giovanni da Modena's dramatic 15th-century frescoes depicting heaven and hell.

Last but not least, peek down at the stone foor along the same aisle. You'll find the remarkable astronomical meridian line designed by the renowned astronomer Giovanni Domenico Cassini in 1655. Stretching exactly 66.8 meters, it stands as the longest indoor meridian line in the world, utilizing a pinhole camera effect where a shaft of sunlight passes through a small aperture 27 meters above the floor to track the solar noon with mathematical accuracy.

For panoramic views over Bologna’s rooftops and the Apennine hills, visit the recently renovated terrace, accessible from Galvani Square by elevator and a short flight of stairs.