The base of the fountain is a basin from the centre of which travertine rocks rise to support four river gods and above them, an ancient Egyptian obelisk surmounted with the Pamphili family emblem of a dove with an olive twig. Collectively, they represent four major rivers of the four continents through which papal authority had spread: the Nile representing Africa, the Danube representing Europe, the Ganges representing Asia, and the Río de la Plata representing the Americas.