Nature
Phlegraean Fields
The Phlegraean Fields is a large volcanic caldera west of Naples, Italy. The Neapolitan Yellow Tuff eruption produced just 50 cubic kilometers. It is, however, one of relatively few volcanoes large enough to form a caldera. It is part of the Campanian volcanic arc, which includes Mount Vesuvius, about 9 km east of Naples. The Phlegraean Fields is monitored by the Vesuvius Observatory. Part of the city of Naples is built over it. The Phlegraean Fields' largest known eruptions have an estimated volcanic explosivity index (VEI) of 7. It is often called a supervolcano in popular media, although th...
What it is
The Phlegraean Fields is a volcanic caldera spread across the area west of Naples, largely hidden because a chunk of the city itself is built over it. Rather than a single cone like Vesuvius, it's a landscape of craters, crater lakes, fumaroles and hot springs, shaped by thousands of years of eruptions and ongoing ground movement. The main appeal for visitors is walking through an active volcanic system at ground level, seeing steaming vents and sulphur-stained earth up close rather than looking at a mountain from a distance.
Getting there
The caldera area is reached from central Naples by local train (Cumana line) or metro toward Pozzuoli, with a journey of roughly 20-40 minutes depending on which part of the Fields you're heading to. A car gives more flexibility for reaching the scattered craters and viewpoints, but parking and small roads can slow things down.
Time to allow
Allow at least half a day to see one or two sites properly, such as a crater walk plus a viewpoint. A full day lets you combine several stops without rushing.
When to go
Go earlier in the day to avoid the strongest heat, since much of the walking is on open, shadeless volcanic ground. Sulphur smells from the fumaroles are constant and can be strong; this isn't seasonal, just something to expect.
Combine it with
- Solfatara (0km) — the volcanic crater within the Fields itself, effectively the same stop.
- Cave of Dogs (2.4km) — a short trip away, a historic natural curiosity tied to the area's volcanic gas activity.
- Bagnoli (2.7km) — a nearby coastal district, worth pairing if you want a sea view after the volcanic terrain.
- Vesuvius Observatory (3.7km) — relevant if you're interested in how the whole volcanic zone, including Vesuvius, is monitored.
Sources: open data from Wikipedia and OpenStreetMap · Updated August 5, 2026 · Edited by the World by City editors
