It was built, probably based on a design by Giacomo Della Porta [1], in 1581, and the work was carried out by the sculptor Taddeo Landini, who was to have made four ephebes and eight dolphins, planned first in marble and then in bronze. The works ended in 1588, and four of the planned dolphins were not put in place because the water pressure did not allow the planned elevation. These dolphins were then used for the fountain of the Terrina, then placed in Campo de 'Fiori and now moved to piazza della Chiesa Nuova. Popular legend tells that Duke Mattei, whose palace overlooks the square that houses the fountain, to amaze his future father-in-law (who did not want to give him his daughter as his wife), had the fountain built in a single night. The next day he made the bride-to-be with her father appear at the window to admire the work. So, so that no one else could enjoy the same spectacle anymore, the young duke had the window bricked up, which thus came to us. The weakness of the legend (in addition to the improbable speed of construction) is that while the fountain dates from 1581-88, the palace was built later, only in 1616.