The area of Piazza Navona in Rome copies the dimensions and the form of the antique Stadium of Domiziano dating from the Roman times; an arena more than 270 metres long and roughly 55 meters large, built around 86 after Christ and able to welcome up to 33000 persons.
After it has been restored by Alessandro Severo and it has found the actual arrangement thanks to the intervention of Pope Innocenzo X, in the square were organised until the 19th century various kinds of spectacles, celebrations and during the month of August, when the square was inundated by closing the flash rings of the fountains, even "naumachie" (naval fights inside an arena).
The name "Piazza Navona" probably founds its origins in the competitions that were taking place in the area; from the Latin word "in agone" in fact, we would have passed during the time to the vulgar "nagone" and definitely to "navona".
Piazza Navona is longitudinally marked by the presence of the three fountains; the lateral "Fountain of Neptune or of the Calderoni" and "Fountain of the Moro" are due to the designs of Giacomo della Porta, while the central "Fountain of the Rivers" was realised by Bernini between 1648 and 1651 after Christ.
In front of this last one we find, on the ruins of the stadium of Domiziano and of an antique basilica which can still be visited from the undergrounds of the building, the church with Greek cross plan of Sant'Agnese in Agone, which, initially projected by G.Rinaldi, was achieved in 1652 by Borromini with the characteristic fašade concave, the twin belfries and the cupola.