Founded in 1564 to highlight the statue of Neptune to which it owes its name, the square was the result of the expansion of the existing space between Palazzo d'Accursio and Palazzo del Podestà through the demolition of a block of buildings. The statue of Neptune was built between 1563 and 1567 by the Flemish sculptor Jean de Boulogne, known as Giambologna, and by Tommaso Laureti, known as Il Siciliano. On one side of the square is the Sala Borsa, since 2001 the Multimedia Civic Library, on the other, next to Palazzo del Podestà, stands Palazzo Re Enzo.

Basilica Di San Petronio

The Basilica of San Petronio, dedicated to the city's patron saint, stands in Piazza Maggiore and is the largest and most important church in Bologna. Construction began in 1390 under the direction of Antonio di Vincenzo. In 1514 Arduino degli Arriguzzi proposed a new Latin cross model that would have exceeded the size of the church of San Pietro in Rome, but, according to legend, Pius IV blocked its construction by soliciting the works for the construction of the Archiginnasio. Famous is the Musical Chapel of San Petronio, the oldest musical institution in Bologna (1436), whose most prestigious symbol is a still functioning organ, which, built around 1470 by Lorenzo da Prato, is the oldest in the world still in use