It is one of the most famous sights of Rome, and of the most successful monuments built in Rome in the 18th century. The fountain was built under Clement XII in 1732-1762 by the project of N.Salvi (finished after Salvi's death by Giuseppe Pannini), who's project was chosen among other 16. The statue of the Ocean is by P.Bracci (1762), the rest of the sculptures and decorative elements were executed by various sculptors.  The fountain occupies entire side of Palazzo Poli and is 20m wide and 26m high.

Two giant tritons conduct the winged chariot of Neptune-Ocean. In the side niches are figures of Health (right) and Abundance (left), both by F.Della Valle; the bas-reliefs above represent the virgin of the legend pointing out the spring to the soldiers, and Agrippa, approving the plans for the aqueduct. The four statues above represent the Seasons with their gifts. At the summit is the coat-of-arms of the Corsini family, with two allegorical figures.

 

Previously here was a simple fountain by L.B.Alberti placed by Nicolas V to celebrate the realization of his project which consisted in reactivation of ancient aqueduct of Agrippa, Acqua Vergine, 20km long and bringing to Rome one of the purest waters in the world. The name "Vergine" (Virgin) derives from the history of its discovering by a little girl in 19 b.C., who showed the water source to the Roman soldiers. The Acqua Vergine also feeds the fountains of Piazza Navona, Piazza di Spagna and Piazza Farnese.

The name "Trevi" may come from "tre vie", i.e. "three streets", referring to the three roads converging here.

There is a tradition that every visitor has to through a coin to the fountain (standing with the back facing the fountain) if they want to return to Rome one more time. This cute superstition comes from an ancient custom when pilgrims were leaving the coins on the tomb of St Peter. The money from the fountain is collected periodically and donated to the Italian Red Cross.