A few blocks from Borromini’s San Carlo alle Quattro Fontane, a life sized muscular Triton is depicted as a merman kneeling on an opened scallop shell. It was executed by Bernini though the use of the natural rock travertine in 1642 to 1643. The Triton is a minor sea god of ancient Graeco-Roman legend. In the fountain, the Triton throws back his head to raise a conch to quench his thirst with the stream of water falling from a shell where a jet of water spurts formerly rising dramatically higher than it does today.

The Triton Fountain was the first of Bernini’s fountains but it was also the last major commission from his great patron, Maffeo Barberini , who died in 1644. The Triton Fountain has a base of four highly detailed dolphin sculptures with open mouths rising from the ocean and tangling their tails upward that entwine the papal tiara with crossed keys and the heraldic Barberini bees in their scaly tails. The fountain was erected to provide water from the Acqua Felice aqueduct. The aqueduct was previously restored by Urban in a dramatic celebration. Urban and Bernini brought a garden feature familiar from garden settings in the suburban villas purposely made for the public, utterly urban setting for the first time at the Triton Fountain in contrast to all the previous fountains of Rome which had been passive basins for the reception of public water.

Bernini was inspired by the triumphant passage concerning Triton, from Ovid's Metamorphoses book. The triumphant passage evoked godlike control over the water. It has Triton blowing into the shell to sound a retreat to the waters of the flood. The beautiful water fountain symbolized the use of water with its power and force. And the passage described the draining away of the Universal Deluge and the return of the life of the world. In addition, the fountain is one of those evoked in Ottorino Respighi's Fontane di Roma. The legend applied to the Trevi Fountain has been extended to the Triton Fountain. That any visitor who throws a coin into the water of these fountains will have their return to Rome guaranteed.