The Fountain of Neptune is a fountain in Rome, Italy, located at the north end of the Piazza Navona. It was once called "Fontana dei Calderari" because it was located close to a small alley with blacksmith's workshops, makers of pots and pans and of other metal based businesses, all of them generating heat.
The restoration of the Roman Aqua Virgo aqueduct in 1570 was immediately followed by the start of work on a continuation water supply pipe towards the district of the old Campo Marzio, which following the diminution of the city's size and importance was left as the most densely populated part of the city. Restoration of a piped water supply in turn permitted the construction of several public fountains.
Wikipedia https://en.wikipedia.org/wiki/Fountain_of_Neptune,_Rome
Address 66 Piazza Navona, Roma 00186, Italy
Coordinates 41°53'59.272" N 12°28'22.873" E