During the early Vedic Age, the Indus and the Sarasvati River were the major rivers of the Indian subcontinent, not the Ganges. But the later three Vedas seem to give much more importance to the Ganges, as shown by its numerous references. Possibly the first European Traveler to mention the Ganges was Megasthenes (ca. 350 – 290 BCE). In Rome's Piazza Navona, "Fontana dei Quattro Fiumi" (fountain of the four rivers) was designed by Gian Lorenzo Bernini and built in 1651. The art-work symbolizes four of the world's great rivers (the Ganges, the Nile, the Danube, and the Río de la Plata), which is to represent the four continents (Australia and Antarctica were unknown then).