The base of the fountain is a basin from the centre of which travertine rocks rise to support four river gods and above them, a copy of an Egyptian obelisk surmounted with the Pamphili family emblem of a dove with an olive twig.

"[1]Public fountains in Rome served multiple purposes: first, they were highly needed sources of water for neighbors in the centuries prior to home plumbing.

However, it is equally plausible that the obelisk might have originated from the Temple of the Gens Flavia on the Quirinal Hill, built by Domitian dedicated to his family cult.

The hieroglyphic inscriptions on the obelisk were of Roman authorship, offering a hymn to Domitian, and the deified emperors Vespasian and Titus, possibly on the occasion of something being restored.

In the fourth century, the obelisk was relocated to the Circus of the emperor Maxentius, located between the Church of St. Sebastian and the tomb of Cecilia Metella along the Appian Way, where it was found and moved to the Fountain.

The circus – as well as the nearby villa and mausoleum – was first believed to be attributed to the emperor Caracalla, until excavations carried out by Antonio Nibby in 1825, in which an inscription identifying the ownership of the site was found.

[5] The dynamic fusion of architecture and sculpture made this fountain revolutionary when compared to prior Roman projects, such as the stilted designs Acqua Felice and Paola by Domenico Fontana in Piazza San Bernardo (1585–87) or the customary embellished geometric floral-shaped basin below a jet of water such as the Fontanina in Piazza Campitelli (1589) by Giacomo della Porta.

Beforehand, wooden scaffolding, overlaid with curtains, had hidden the fountain, though probably not the obelisk, which would have given people an idea that something was being built, but the precise details were unknown.

The celebrations were announced by a woman, dressed as the allegorical character of Fame, being paraded around the streets of Rome on a carriage or float.

Bernal notes that "she went gracefully through all the streets and all the districts that are found among the seven hills of Rome, often blowing the round bronze [the trumpet], and urging everyone to make their way to that famous Piazza."

The report mentions the "enraptured souls" of the population, the fountain, which "gushes out a wealth of silvery treasures" causing "no little wonder" in the onlookers.

Pasquinade writers protested against the construction of the fountain in September 1648 by attaching hand-written invectives on the stone blocks used to make the obelisk.