Just up from the Chiesa di San Pietro in Montorio, this monumental white fountain was built in 1612 to celebrate the restoration of a 2nd-century aqueduct that supplied (and still supplies) water from Lago di Bracciano, 35km to the north of Rome. Four of the fountain’s six pink-stone columns came from the facade of the old St Peter’s Basilica, while much of the marble was pillaged from the Roman Forum. Originally the fountain had five small basins, but these were replaced by a large granite basin, added by Carlo Fontana, in 1690.