The volcanic caldera near Naples, Italy, known for its supereruption potential is Campi Flegrei. Also called the Phlegraean Fields, it is a broad volcanic system west of Naples rather than a single cone-shaped mountain. Its caldera contains dozens of craters and volcanic structures, many hidden beneath the Gulf of Naples.
Campi Flegrei’s most important eruptions include the Campanian Ignimbrite eruption roughly 39,000 years ago and the Neapolitan Yellow Tuff eruption about 12,000 years ago. The older event reached an estimated Volcanic Explosivity Index of 7 and spread ash across much of Europe. That enormous history is why the area is often described in popular media as a “supervolcano,” although the strict VEI-8 definition is debated.
The name means “burning fields,” reflecting the region’s fumaroles, hot springs, and ground movement. Nearby Pozzuoli is known for bradyseism—slow uplift and subsidence caused by changes in the volcanic and hydrothermal system. Mount Vesuvius is also near Naples, but it is a separate volcano east of the city. Campi Flegrei last erupted in 1538, when Monte Nuovo formed during an eight-day eruption.