Fountains of St. Peter's Square, Renaissance fountains in St. Peter's Square, Vatican City

The Fountains of St. Peter's Square are two twin fountains on the major axis of the elliptical square, aligned with the Egyptian obelisk at the center. Each has an octagonal base, a wide irregular basin, and a lower granite vasque topped by an inverted, scale-covered cup that breaks the jet into a veil of droplets.

A fountain stood here from 1490, built under Innocent VIII and restored under Alexander VI in 1500. After Paul V restored the Aqua Traiana as the Acqua Paola in 1612, Carlo Maderno rebuilt it on an octagonal base, keeping the lower granite basin. In 1667 it was moved onto the square's main axis, and a matching twin, credited to Carlo Fontana, was inaugurated on 28 June 1677.

The two basins are not identical twins: the north fountain carries the coat of arms of Paul V and dolphin reliefs on its octagonal base, the south one that of Clement X. Romans nicknamed the Maderno fountain "la fontana del tritone" for its mushroom-shaped cap of stone scales, which breaks the jet into a veil of drops.

Both fountains stand on the long axis of the elliptical square, in line with the Egyptian obelisk raised by Sixtus V in 1586; the Maderno fountain is on the north side, the Bernini twin on the south. Water still arrives from the Acqua Paola on the Janiculum, and a restoration under Paul VI, recorded on the left-hand fountain, cut the jets and added a recycling system.

The Flemish lawyer Theodor Ameyden wrote in 1641 that the jet from the Maderno fountain "seemed to rise in the air like a veritable river", calling it the most beautiful fountain in Europe. Fed by the Acqua Paola on the Janiculum, it threw water about twenty feet high without pumps.