Is It Time to Start Worrying About an Eruption at the Campi Flegrei?

It's been 485 years since the last eruption at Italy's Campi Flegrei. As you might guess, a lot has changed. When Monte Nuovo formed in 1538, the population in and around Naples was a few hundred thousand people. Today, that number is closer to three million people. The 1538 eruption produced a small cinder cone in Pouzzuoli at the mouth of the Bay of Naples, burying parts of medieval villages. With increased restlessness under the Campi Flegrei, Italy has to contend with the fact that even a small eruption like 1538 might require evacuating half a million people from a densely settled area.