The magnificent Fontana dell' Acqua Paola (1608-12), which is also known simply as Il fontanone (the big fountain), was commissioned by Pope Paul V (r. 1605-21), and designed by Giovanni Fontana (1540-1614) & Flaminio Ponzio (1560-1613).
The Fontana dell' Acqua Paola, which was the first major fountain to be erected on the left bank of the Tiber, was fed by the Aqua Trajana, an ancient aqueduct built by the emperor Trajan (r. 98-117). The aqueduct was restored by Pope Paul V and renamed the Acqua Paola. The façade of the fountain is adorned with six granite columns, which support an architrave bearing an inscription that proclaims: ANNO DOMINI MDCXII PONTIFICATVS SVI SEPTIMO (In the year of the Lord, 1612, the seventh year of his pontificate).
The longer inscription reads: PAVLVS V PONT MAX / AQVAM MVNIFICENTIA SVA / IN SVMMVM IANICVLVM PERDVCTAM / CITRA TIBERIM TOTIVS VRBIS VSVI / DEDVCENDAM CVRAVIT / ANNO DOMINI MDCXIII / PONTIFICATVS OCTAVO (Paul the Fifth, Pontifex Maximus, through his munificence, had the aqueduct, which extended to the summit of the Janiculum, brought down to the other side of the Tiber for the use of the whole city, in the year of the Lord 1613, the eighth of his pontificate).
The fountain sports images of a dragon and an eagle, the two creatures which make up the Borghese coat of arms, the illustrious family to which Pope Paul V belonged.