The Piazza Grande (now Piazza IV Novembre) has always been the urban, political and monumental fulcrum of Perugia. It was the central square of the Etruscan city, and the Forum when Perugia passed under the dominion of Rome. The city's main streets crossed here and this is the meeting the point where the five strade regali roads began and spread outwards during the Medieval development of the town.

The square was at one time occupied by the bishop’s citadel, but this was demolished to pave the way for the public buildings of the free city.

The symbol of the free city of Perugia, the fountain that stands at the centre of the square is considered one of the finest still in existance.

It was completed between 1275 and 1278, at the arrival point of the Monte Pacciano acqueduct. Fra Bevignate supervised construction, which was carried out by the Pisan sculpturers Nicola (father) and Giovanni (son) Pisano. The fountain is made up of two polygonal basins in white and pink stone, placed one above the other. This structure is in turn surmounted by a bronze basin with a group of three bronze nymphs holding an urn, from where the water gushes. Probably later in date, this group was once topped by four griffins that have since been dismounted and are now housed in the Galleria Nazionale dell’Umbria.

The panels on the lower basin represent salient episodes from the Old Testament (the seduction of Adam by Eve, and of Samson by Delilah). The founding of Rome, a major example for Perugia, is also featured, as well as a kind of agricultural calendar with the related astrological signs. These are followed by the seven “liberal arts” and a personification of Philosophy. Between the “mechanical” and the “liberal arts” is the griffin, Perugia's heraldic symbol, and the lion, the symbol of the Guelph faction of which Perugia was a supporter. During the Middle Ages Italy was divided into two factions, the Guelphs who upheld the claims to temporal power of the Papacy, and the Ghibellines who believed that temporal power should be in the hands of the Holy Roman Emperor. Two eagles conclude the cycle and may lead one to the mistaken conclusion that they represent the symbols of the Holy Roman Emperor. Since the eagle is also the symbol of the city of Pisa, it is more likely that these panels act as Giovanni Pisano's signature.

The upper polygonal basin stands on 24 small columns, each surmounted by a statue. The statues represent characters from the mythological tale concerning the founding of Perugia, as well as references to its political and territorial role. Solomon and other biblical characters are in fact featured, including Moses, John the Baptist, the Archangel Michael and the Archpriest Melchisedech. There is also a personification of Rome, the Church, Theology and the saints Peter and Paul.