The Fontana dell'Acqua Paola is a monumental fountain located on the Janiculum Hill, near the church of San Pietro in Montorio. 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 left 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.