The only fountain in Rome that can truly compare to Trevi Fountain for its beauty and majesty. Indeed, the form of the fountain served as an inspiration for the later Trevi Fountain.

Although I live in Rome since decades, I never heard of this beautiful construction until I watched an Italian movie: "The Great Beauty". Most probable root cause is the fact that fountain is not located in the city center. I was shocked by its beauty when I saw it in the film. However, coupled with its surroundings, it looks much better in realty.

The Fontana dell'Acqua Paola also known as Il Fontanone ("The big fountain") is a monumental fountain located on the Janiculum Hill, near the church of San Pietro in Montorio, in Rome, Italy. It was built in 1612 to mark the end of the Acqua Paola aqueduct, restored by Pope Paul V, and took its name from him. It was the first major fountain on the right bank of the River Tiber.

The Fontana dell'Acqua Paola was inspired by the popularity of the Fontana dell'Acqua Felice, built in 1585-88 by Pope Sixtus V. Pope Paul V decided to rebuild and extend the ruined Acqua Traiana aqueduct built by the Emperor Trajan in order to create a source of clean drinking water for the residents of the Janiculum Hill, who were forced to take their water from brackish springs or from the polluted Tiber.

The fountain was designed by Giovanni Fontana, whose brother had worked on the Fontana dell'Acqua Felice, and Flaminio Ponzio. They used white marble from the nearby ruins of the Roman Temple of Minerva in the Forum of Nerva, and constructed a massive gateway of five arches for the arrival of the water. At the top of the fountain are the papal tiara and keys, above the Borghese family coat of arms of an eagle and a dragon, supported by angels. The inscription praises Pope Paul in poetic terms for bringing water to the residents of the district.

Unlike the Fontana dell'Acqua Felice, which had an abundance of statues on biblical themes, the theme of the Fontana dell'Acqua Paola was water. Five abundant streams poured through the arches into five marble basins. In 1690 Carlo Fontana designed an additional semicircular pool for the water which overflowed from the marble basins. Marble posts were put in place to keep coachmen from watering their animals in the fountain, but the pool was tempting to many local residents, who bathed in the water. An ordinance was issued in 1707 forbidding residents to bathe in the fountain.