Curving along the Bay of Pozzuoli, this land took the name Phlegraean Fields (Campi Flegrei) on account of its volcanic nature: phlegreaen comes from a Greek verb meaning "to burn". Rising up out of the ground and the sea, hot springs, fumaroles, gases and sulphurous vapours demonstrate significant subterranean activity; several craters have now become lakes. The seaside resorts of the Bay of Pozzuoli are also pleasant ports of call.