I felt the heat before I saw it. Standing at the edge of the Solfatara crater, the ground under my feet was warm, and the air smelled sharply of sulfur. Steam hissed from vents in the earth, some reaching over 160°C. This is the Campi Flegrei, a massive volcanic caldera west of Naples, and it is one of the most geologically active places on the planet. Unlike the single peak of Vesuvius, this area is a sprawling, eight-mile-wide field of 24 craters and fumaroles, where the ground literally rises and falls in a process called bradyseism. I came here expecting ruins, but I left realizing this is the only place in the world where you can see an active volcano, a Roman amphitheater, and natural hot springs all in one afternoon.
If you have already seen Pompeii and want something less crowded but equally fascinating, Campi Flegrei is your answer. It is not a polished tourist site — it is raw, scientific, and deeply historical. You need a car or a willingness to use local trains, but the payoff is a day that feels like you are walking through a living geology textbook and a Roman history book at the same time.
History buffs
Volcano enthusiasts
Slow travelers
La Solfatara: Walking on a Sleeping Volcano
This is the most visceral stop on the itinerary, and the one that will stick with you longest.
The Solfatara is an elliptical crater measuring 770 by 580 meters. It is still active, though dormant, and the fumaroles here are not just for show — they are jets of steam and boiling mud that have been hissing for centuries. I watched a small pool of mud bubble and pop, and I could feel the heat radiating from the ground through the soles of my sneakers. The site is essentially an open-air geology laboratory, and you can walk right up to the vents (carefully, on marked paths).
Arrive at Solfatara right when it opens in the morning. By 10:30 AM, the tour groups from Naples start arriving, and the narrow paths around the crater get crowded. Wear closed-toe shoes — the ground is uneven and warm in spots.
The Flavian Amphitheater: Rome’s Third-Largest Arena
Most people do not realize that the third-largest Roman amphitheater in Italy is not in Rome or Capua — it is in Pozzuoli.
The Flavian Amphitheater in Pozzuoli once held up to 40,000 spectators. It is smaller than the Colosseum, but the underground corridors are remarkably well-preserved. You can walk through the same passageways where wild beasts were caged and lifted into the arena via a complex system of pulleys. The site is far less crowded than the Colosseum, and on a weekday morning, I had entire sections of the underground to myself.
The amphitheater is a short walk from the Pozzuoli train station. Combined ticket options with other Campi Flegrei sites are available at the ticket office.
Rione Terra and the Macellum: Layers of History
Pozzuoli’s ancient core tells the story of bradyseism better than any museum exhibit.
Rione Terra is the original heart of Pozzuoli, abandoned in the 1970s after a bradyseism crisis caused nearly two meters of ground uplift. The entire district was evacuated, and it sat empty for decades. Today, it has been restored, and you can walk on Roman basalt paving stones that sit directly below a medieval and baroque city built on top. The Macellum, often called the Temple of Serapis, was actually a Roman market. Three standing columns show clear marks from marine mollusks — proof that the ground here has sunk below sea level and risen again multiple times over the centuries.
The Macellum is partially submerged depending on the current bradyseism phase. When I visited, water covered the lower floor, so you view it from above. Check recent visitor reports before going if you want to see the full structure.
Baiae: The Roman Las Vegas Underwater
If you want to see where Roman emperors actually relaxed, you need to go to Baiae — or what is left of it.
Baiae was the playground of the Roman elite. Emperors like Nero and Hadrian built sprawling villas here, complete with thermal baths that spilled down the cliffside like an ancient Positano. Today, much of Baiae is underwater, submerged by the same bradyseism that lifted Rione Terra. The Underwater Archaeological Park of Baiae offers glass-bottom boat tours, allowing you to see Roman statues, mosaics, and entire room floors still intact beneath the waves. For a closer look, you can also book a guided snorkeling or diving tour.
Cuma and the Cave of the Sibyl
This is where Greek mythology meets Roman engineering, and it is one of the most atmospheric sites in the entire caldera.
The Archaeological Park of Cuma is the site of the first Greek colony in western Europe, founded around 730 BC. The main attraction is the Cave of the Sibyl, a 130-meter-long trapezoidal corridor cut into the rock. According to Virgil, this was where the Cumaean Sibyl wrote her prophecies on oak leaves. The cave is dark, narrow, and eerily quiet. At the top of the acropolis, you will find the remains of a Greek temple to Demeter, later rebuilt as a Roman temple to Jupiter, and then topped with a Byzantine basilica. The layers of history here are visible in the stonework itself.
Bring a flashlight or use your phone’s light inside the Sibyl’s cave. The floor is uneven, and the lighting is minimal. The walk up to the acropolis is steep but short — about 10 minutes from the entrance.
Piscina Mirabilis: A Cathedral of Water
This is one of those places that makes you stop and just stare.
Piscina Mirabilis in Bacoli is a massive Roman cistern that supplied water to the Roman navy fleet stationed at Misenum. It is 70 meters long, 25 meters wide, and supported by 48 pillars. The space feels more like a cathedral than a water tank. The acoustics are incredible, and the light filtering through the openings at the top creates a quiet, almost sacred atmosphere. It is less visited than the amphitheater or Solfatara, which makes it a good spot for a moment of calm.
Getting Around: Train vs. Car
The Campi Flegrei sites are spread across several towns, so your transport choice matters.
| Factor | Ferrovia Cumana Train | Car |
|---|---|---|
| Cost | Around €3-5 per ride from Naples | Parking fees + fuel (€10-20/day) |
| Flexibility | Fixed schedule, stops at main towns | Stop anywhere, go at your own pace |
| Parking | None needed | Limited at Solfatara and Baiae; paid lots in Pozzuoli |
| Best for | Solo travelers, no car rental | Families, groups, off-the-beaten-path stops |
The Ferrovia Cumana runs from the Montesanto station in Naples to Pozzuoli, with stops near most major sites. It is cheap and reliable, but you will need to walk or take local buses between stops. With a car, you can visit Cuma, Baiae, and Bacoli in a single day without waiting for connections. I drove, and it made the day significantly easier, especially with the kids.
- Start at Solfatara early (8:30 AM) to beat the crowds and the heat.
- Combine the Flavian Amphitheater and Rione Terra in Pozzuoli for a half-day of Roman history.
- If you have a car, add Baiae’s underwater park and Cuma’s acropolis for a full-day itinerary.
Where to Eat in Pozzuoli
The seafood here is excellent, and the setting is often right on the water.
Pozzuoli is famous for its octopus and anchovy dishes. I had lunch at Le Cantine dell’Averno, a restaurant set on a vineyard overlooking Lake Avernus. The potato with octopus was simple and perfect, and the marinated fish was fresh. They also serve Pape Satan, a local wine that gets its earthy character from the volcanic soil. For a more casual option, try Scapricciatiello in central Pozzuoli for pizza and fried seafood.
Before You Visit Campi Flegrei
Is Campi Flegrei safe to visit right now?
The area is under a yellow alert for volcanic risk, which means it is monitored constantly. Small earthquakes, called scosse, happen regularly. The sites are open and safe for visitors as long as you stay on marked paths.
How much time do I need?
A full day is enough to see Solfatara, the Flavian Amphitheater, Rione Terra, and one more site like Baiae or Cuma. If you want to do the underwater park and the acropolis, plan for two days.
Is it worth visiting if I have already seen Pompeii?
Yes, and that is the main reason to come. Campi Flegrei offers a completely different experience — fewer crowds, active geology, and a chance to see Roman ruins that are still being shaped by the earth.
What is the biggest disappointment?
The Macellum is often partially flooded, and you cannot walk through it. Also, some sites have limited English signage, so download a guide or bring a book on the area.
Can I bring kids?
Yes, but keep them close at Solfatara — the ground is warm and the fumes are strong. Lily and Ethan found the bubbling mud pools fascinating, but I had to watch them constantly near the fumaroles.
Why This Corner of Italy Stays With You
I have been to Pompeii half a dozen times, and I always left impressed by the scale of the disaster. Campi Flegrei left me impressed by the scale of the earth itself. Standing at Solfatara, watching steam rise from a crater that has been active for thousands of years, I understood why the Romans built their baths here and why Virgil set his underworld at Lake Avernus. This is not a place you visit to check a box. It is a place that changes how you see the ground beneath your feet. For more on traveling through Italy’s less crowded corners, read about Italy’s off-beat Baroque towns that offer affordability and beauty.
Sources and further reading
Italy Tripper. “Campi Flegrei: Between Volcanoes and Myths.” 🔗
Italy Tripper. “Campi Flegrei: Between Volcanoes and Myths.” 🔗
The Guardian. “The ancient marvels of Campi Flegrei.” 🔗
BBC Travel. “The uncrowded — and equally fascinating — alternative to Pompeii.” 🔗
Related reading on Emily in Italy
Hike Italy’s Cinque Terre’s Colorful Villages — A practical guide to walking the coastal trails with tips on timing and avoiding the midday crowds.
Parma: Where Pork and Pasta Meet Culture — A food-focused itinerary through Parma’s markets, trattorias, and cheese producers.
Puglia’s Caves to Rome’s Rooftops: Italian Summer Echoes — A comparison of two very different Italian summer experiences, from coastal cave towns to urban rooftops.