With an area three times larger than Pompeii, Baia, about 15 km from Naples and within the volcanic area of the Phlegraean fields, is the largest underwater archaeological site in the world. In 100 BC Pompeii is an ordinary city of small traders crouched on the slopes of Mt. Vesuvius, while Baia gains a peculiar reputation: it gradually becomes the ancient Las Vegas or Monte Carlo of the Roman Empire, a real posh center for noble gens and the powerful . Nestled in the center of the Gulf of Pozzuoli, Baia is flanked on one side by the port of Puteoli (ancient Pozzuoli) and on the other by the port of Capo Miseno.