The personifications of the Adriatic and Tyrrhenian Seas, inspired by Roman models placed by Michelangelo in the nearby Campidoglio, dominate the two fountains on either side of the entrance.
On either side of the main entrance are two fountains: the fountain to the east with The Adriatic Sea is by Emilio Quadrelli (1863-1925) from Milan; the fountain to the west with The Tyrrhenian Sea by Pietro Canonica (1869-1959) from Piedmont. Commissioned in 1908, the two artists delivered the works in 1911, in time for the inauguration of the monument on 4 June 1911. The model for the two figures are the statues of rivers that, in ancient times in the Baths of Constantine, were placed by Michelangelo in the Renaissance on the Piazza del Campidoglio, at the foot of the steps of the Palazzo Senatorio.
Quadrelli represents The Adriatic Sea lying with his gaze turned towards the east, while he brings his right hand to his forehead, as if protecting himself from the light, and rests his left hand on the lion's head, the symbol of Venice.
Canonica presents The Tyrrhenian Sea lying with its face turned towards the east. One hand rests on the head of the Capitoline She-wolf, the best known of Rome's symbols, the other on a bas-relief adorned with the figure of Parthenope, which alludes instead to the city of Naples. In Greek mythology, in fact, the siren Parthenope with her song bewitched sailors, who lost control and ended up against the rocks. When Ulysses managed to pass unscathed, Parthenope killed herself. Her body was carried by the waves to the shores of the Gulf of Naples where it became an object of veneration.
The two fountains are also a fine example of hydraulic engineering. They required an enormous amount of water and were therefore very costly to operate. To solve the problem, two motor-pump units were installed, which took the water from the lower basin and lifted it up to the upper basin, thus ensuring its recirculation. At the same time, a reservoir with a capacity of 500 cubic metres was built to allow the fountains to be filled quickly after cleaning and also to raise and lower the gate.