As Rome rose and took over the Italian peninsula, southern Italy and Sicily were full of ancient Greek colonies (the Romans called the region 'Magna Graecia'). One of the oldest Greek colonies in Italy was Cumae near Naples (also a Greek colony). One of the best and most significant ancient attractions at Cumae is the Cave of the Sibyl.

The Cave of Sibyl is located near the ancient Roman Sin City of Baiae, of which half of the old city is now submerged in the sea. See the three 'temples' of Baiae which are actually the ruins of three large ancient Roman thermal baths. This area outside of Naples is unique for having Greco-Roman ruins on land, submerged in the water, and underground in caves.