It is said that water probably reached the Piazza del Campo in 1342, after 8 years of work, and that the Sienese celebrated with great enthusiasm. The fountain, then called Gaia (or 'joyful'), was constructed the following year, in 1343. But the first fountain of the 1300s was later replaced in 1419 by that of Jacopo della Quercia and then again by a copy by Tito Sarrocchi in 1858.
The marble panels of Jacopo della Quercia can be seen today in a room of Santa Maria della Scala, the old hospital looking onto the Piazza del Duomo.
The Gaia Fountain of Jacopo della Quercia is one of the most important works of the Italian 1400s and is both Gothic and Renaissance in style.
Charles V, after visiting the Sienese "bottini", is supposed to have exclaimed that Siena was two cities in one, each as beautiful as the other, the first underground, the second above. Water was conveyed to Piazza del Campo through a master-conduit, most likely first utilized around 1342. "The Sienese saluted the event with great rejoicing", wherefore the fountain, appropriately named Fonte Gaia (Joyous Fountain), was built the following year (1343).
The XIV century Fonte Gaia, about which we have practically no information, was replaced in 1419 by Jacopo della Quercia's and then by Tito Sarrocchi's free adaptation of it in 1858. The two statues of Rhea Silvia and Acca Larentis, That Jacopo had placed at each end of his fountain, were omitted from Sarrocchi's copy.
The original sculptures by Jacopo della Quercia are now in a room in the old Ospedale di St. Maria della Scala that overlooks Piazza Duomo. Although its present state is decidedly lamentable, Jacopo's Fonte Gaia is still one of the most important sculptures produced in XV century Italy during the transition from the Gothic to the Renaissance styles. The Madonna and Child, a symbol taken from Lorenzetti's Allegory of Good Government, is flanked by two angels, the Theological and Cardinal Virtues and by Justice.
Successive changes in the project led Jacopo to add the statues of the Expulsion from Paradise, the Creation of Adam as well as the two statues of Acca Larentis and Rhea Silvia (respectively mother and nurse of Romulus and Remus, symbolizing Charity and Liberality). These were the first two statues of female nudes to stand in a public place, who were neither Eve nor a repentant saint.