Because of its size, the statue of Neptune is called “il Gigante” (the Giant), or “al Żigànt” in Bolognese dialect. It was built in 1566 according to the inscription at the base of the fountain, “to serve the people”; namely, to beautify the Piazza Maggiore because it was a stop on the route between the Archiginnasio and the Palazzo del Comune. Freshly elected Cardinal Carlo Borromeo was responsible for wanting the Piazza Maggiore improvements; the work was meant to symbolize the happy rule of Pope Pius IV, his maternal uncle.
A young Flemish man, Jean de Boulogne, was called in from Douai to handle the undertaking. Known as Giambologna, he was eager to prove himself after having just lost the competition for the Fontana del Nettuno in the Piazza della Signoria in Florence.
An entire city block was razed to create the fountain, with both houses and shops paying the price. The statue of the god Neptune was placed at the exact point where the cardo and the decumanus – the proto-typical main streets of a Roman city - intersected. The fountain was supplied with water piped in from an ancient underground cistern and a spring found below a convent.
Just steps from the city’s political core, the fountain was an immediate hit with the vegetable sellers, launderers, and artisans -- so much so that a punishment of 50 lashes was given to women and children caught using it for bathing, while the punishment for men was “ (a torturous and crippling procedure involving tying the arms behind the back and cranking up on them to the point of dislocation).
It is said that Giambologna wanted to fashion Neptune with larger genitalia but naturally met with opposition from the Church. However, the sculptor would not be swayed: he designed the statue so that from a particular angle the thumb of the outstretched left hand lines up with the groin area, making it look like an erect penis. According to the prelates, the women of Bologna were so disturbed by the sight that the Church had to put bronze pants on the statue. Actually, the entire fountain has a strongly erotic quality: just take a look at the voluptuous nymphs spraying their breasts with water!
There is also a noteworthy superstition. In order to pass an important exam, students run two counter-clockwise laps around the fountain. Apparently this practice comes from Giambologna himself who - being extra careful while planning the fountain because of his earlier “failure in Florence” - continually circled the base deep in thought. And good luck certainly isn’t lacking here. The trident the god is brandishing has become one of the world’s most well known symbols: that of Maserati, the Bologna based automobile manufacturer.