Well there was the 1906 earthquake. What do you think will come first, Yellowstone or the Campi Flegrei? There was some very worrying heave-ho in Pozzuoli in the 1980s and there seems to be a big blob of magma on the move not far from Naples. Dragged Mrs Steve there a couple of years ago (nearly got meself mugged on the underground in Naples for my troubles!) and we found the Solfatara crater satisfyingly active, dangerous and smelly. Get off the train at Pozzuoli and walk up the hill. Very potentially phreatic!

Didn't the Campanian Ignimbrite eruption at Campi Flegrei allegedly wipe out the Neanderthals? Bet THEY thought it couldn't get much worse!