The backdrop for the Trevi’s fountain is the Palazzo Poli, given a new facade with a giant order of Corinthian pilasters that link the two main stories. Taming of the waters is the theme of the gigantic scheme that tumbles forward, mixing water and rockwork, and filling the small square. Tritons guide Oceanus’ shell chariot, taming seahorses (hippocamps).
In the center is superimposed a robustly modelled triumphal arch. The center niche or exedra framing Oceanus has free-standing columns for maximal light-and-shade. In the niches flanking Oceanus, Abundance spills water from her urn and Salubrity holds a cup from which a snake drinks. Above, bas reliefs illustrate the Roman origin of the aqueducts.