The Phlegraean Fields stretch west of Naples and include more than twenty craters and volcanic features. At first glance, they may not look like a typical volcano, but beneath the surface lies a vast volcanic system that geologists are closely monitoring.
What are the Phlegraean Fields?
The name Campi Flegrei comes from the Greek word phlegraios, meaning “burning.” The area was formed tens of thousands of years ago by a series of massive eruptions that fundamentally shaped the entire region of Campania. Today, you’ll find fumaroles, hot gas vents, thermal springs, and craters here—all reminders that the volcano beneath the surface is still active. That is precisely why the Campi Flegrei are among the most fascinating geological sites in Italy.
Some eruptions of the Campi Flegrei supervolcano even created small islands (such as Ferdinandea), which later sank back into the sea—either due to erosion or tectonic movements.
Solfatara
The most famous part of the area is the Solfatara crater near the town of Pozzuoli. It is famous for the clouds of steam and sulfur fumes that rise from cracks in the ground. However, following a tragic accident in 2017, the site was closed, and access is now governed by current safety measures. That doesn’t mean you’ll miss out on the experience, though. The Phlegraean Fields offer a number of other spots from which you can observe signs of volcanic activity or admire the landscape shaped by eruptions.
A Landscape in Constant Flux
One of the most interesting phenomena in the area is so-called bradyseism —the slow rising and sinking of the Earth’s surface caused by the movement of magma and gases underground. This process is particularly evident around the city of Pozzuoli, where the elevation of the coastline has changed by about 1.4 meters over the centuries. Historically, similar ground deformation preceded the 1538 eruption of Monte Nuovo, when a new volcanic hill formed within a few days and altered the coastline of the Tyrrhenian Sea. Activity has been increasing in recent years, but experts repeatedly emphasize that there is no immediate threat of an eruption.
It is precisely because of bradyseism that some ancient structures were partially submerged beneath the sea and later reemerged. The Phlegraean Fields are thus a living example of the fact that the Earth is constantly in motion.
What’s worth visiting?
In addition to the volcanic landscape itself, you can visit the historic town of Pozzuoli, the Roman Flavian Amphitheater, or the Cumae Archaeological Park, where, according to ancient legends, the famous Cumaean Sibyl once resided. Nearby is also the Baia Underwater Archaeological Park, featuring the remains of Roman villas submerged by the sea.
Thanks to its combination of natural and historical attractions, this area is an ideal destination for a day trip from Naples. You can purchase tickets online.
Is it safe to visit the area?
Yes, but it’s important to stay informed about the latest updates. The Phlegraean Fields are continuously monitored by Italian volcanologists and authorities. During periods of increased seismic activity, some sites or hiking trails may be temporarily closed. Therefore, it’s a good idea to check the current conditions before visiting and to respect any restrictions that may be in place.
One of the most interesting places in Italy
The Phlegraean Fields prove that the greatest natural wonders aren’t always visible at first glance. Instead of a classic volcanic cone, you’ll discover a landscape full of craters, sulfur fumes, thermal springs, and traces of ancient eruptions. If you’re fascinated by geology, history, or natural phenomena, you’ll be hard-pressed to find a similarly unique place in Italy.
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