Campi Flegrei - volcanic landscapes and the submerged Bay of Baia
West of Naples, the Campi Flegrei caldera combines Greek foundations, Roman holiday villas, thermal water, local wine and ground that still moves. Pozzuoli, Baia, Bacoli and Cuma need their own route rather than a short add-on to Pompeii.
In a nutshell: use Pozzuoli for the first orientation, then follow the caldera towards Baia, Bacoli and Cuma. Rione Terra, the Anfiteatro Flavio and the Tempio di Serapide explain the ancient port; the underwater park at Baia reveals Roman villas below the sea; Cuma brings Greek mythology and the Sibyl's cave; Piscina Mirabilis and Lago Fusaro complete the western loop. Keep access and weather flexible because the area is volcanic, archaeological and not uniformly connected by public transport.
Understand the caldera
Campi Flegrei means burning fields. The broad caldera west of Naples has experienced repeated uplift, sinking and earthquakes as magma shifts below the surface. Bradyseism describes this slow movement of the ground: it helped place the ancient harbour of Baia about 5 m below today's sea and created Monte Nuovo during an eruption in 1538. The region is active, but it is also a lived-in landscape of towns, vineyards, beaches and archaeological parks. Follow local notices and never enter restricted volcanic or military areas.
| Option | Useful for | What to know |
|---|---|---|
| Metro line 2 | Central Naples to Pozzuoli Solfatara | A simple first link to Pozzuoli; check current service |
| Cumana and Circumflegrea | Montesanto, western Naples and parts of the caldera | Useful rail lines, but allow for delays and uneven frequencies |
| Car | Baia, Bacoli, Cuma, Lago Fusaro and Capo Miseno | The area is spread out and summer traffic can be considerable |
| Taxi or organised transfer | Baia Sommersa and a group day | Reserve the water activity first and leave a generous arrival buffer |
Pozzuoli: the ancient port
Pozzuoli was a commercial and strategic port whose volcanic dust, pozzolana, helped Roman builders develop durable concrete. Start at Rione Terra, an abandoned Greek and Roman quarter revealed after bradyseism forced residents to leave in 1970. An acropolis, temples and buried roads now form an open-air archaeological route. Nearby, the Tempio di Serapide is actually the surviving part of a food market; its columns also helped residents read the changing level of the ground over time.
Rione Terra
Pozzuoli's ancient quarter, where Greek and Roman layers lie below the modern town. The district was evacuated after severe ground movement and is now a striking archaeological route above the harbour.
Anfiteatro Flavio
A large Roman amphitheatre in central Pozzuoli, built for the public life of the port. It works well as the first stop before moving deeper into the caldera.
Thermal water at Stufe di Nerone
The Terme Stufe di Nerone is a sulphur-thermal complex near Baia. Its hot vapours and baths continue a wellness tradition associated with Roman Pozzuoli and offer a different way to read the volcanic landscape. Check the current admission, treatment and health requirements before planning a full spa day. Campi Flegrei DOC wine makes a natural follow-on, but do not combine a hot treatment with alcohol or a long drive without a break.
Baia: Rome beneath the water
Baia was the holiday coast of wealthy Romans, a place of villas, baths and extravagant waterfront life. Later volcanic movement lowered parts of the coast, leaving mosaics, walls and sculpture underwater. The Parco Archeologico Sommerso di Baia is the most distinctive experience in the area: Centro Sub Campi Flegrei organises guided snorkelling and diving visits for different levels, with excursions listed from €25 per person for snorkelling. Reservations are necessary, and the tide, weather and safety briefing determine the final route.
Parco Archeologico Sommerso di Baia
Submerged Roman villas, mosaics and copies of ancient statues lie below the water around Baia. The protected park is visited with authorised guides rather than independently.
Official site →Castello di Baia and the museum
The Aragonese castle dominates the promontory at the mouth of the bay. It was built between 1490 and 1493 and later enlarged under Spanish rule. The Museo Archeologico dei Campi Flegrei displays Greek and Roman finds from the surrounding towns, including statues recovered from the submerged park and replaced underwater by copies. The visit makes the relationship between the visible coast and the sunken city much easier to understand.
Terme di Baia and Piscina Mirabilis
The archaeological complex of Terme di Baia preserves the enormous bath culture that made the coast famous in antiquity. Look for the Tempio di Mercurio, an indoor bath and the upside-down fig tree growing through one of the roof arches. In Bacoli, Piscina Mirabilis is a monumental Roman drinking-water cistern built to supply the fleet at Misenum. Its access has changed during restoration, so check the current opening status before making it the centre of a driving day.
Lago Fusaro and Capo Miseno
Lago Fusaro is one of the caldera's lakes and the setting for the octagonal Casina Vanvitelliana, a Bourbon hunting lodge on an islet that later became a favourite of visiting dignitaries and film crews. Finish the western loop at Capo Miseno for views across the crater, the bay and the islands. The landscape is open and exposed, so carry water even when the day begins in a shaded museum.
Cuma: the Greek beginning
The Cumaean Greeks established Cuma on the mainland after first settling on Ischia. The archaeological park preserves the acropolis, the Byzantine Tower and terraces associated with the temples of Apollo and Jupiter. The cave of the Sibyl is the emotional centre of the visit: Greek and Roman writers connected the site to prophecy, the underworld and the journey described in the Aeneid. Walk the park as a landscape, not just a set of ruins, because the sea and caldera explain why this settlement mattered.
A day in Cuma and Baia
- 01Begin at Cuma before the heat, allowing time for the acropolis, terraces, Byzantine Tower and Sibyl's cave.
- 02Continue towards Baia for the Museo Archeologico dei Campi Flegrei and the Terme di Baia, checking opening hours before you leave Naples.
- 03If you have reserved a snorkelling or diving visit, schedule it with at least 30 minutes of arrival margin and keep the water activity before a long drive.
- 04Visit Piscina Mirabilis or Casina Vanvitelliana only after confirming access, then end at Capo Miseno or a Bacoli waterfront table.
Wine from volcanic soil
Campi Flegrei's vineyards grow in volcanic soil and retain ancient local varieties. Falanghina and Piedirosso carry the Campi Flegrei DOP name and are described as fresh, mineral wines shaped by the sea and ash-rich ground. Cantina degli Astroni offers visits by arrangement near one of the area's craters. Treat a winery visit as a destination in its own right rather than trying to add it between two timed archaeological entries.
| Experience | Where | Planning note |
|---|---|---|
| Roman underwater archaeology | Baia | Book Centro Sub Campi Flegrei; snorkelling and diving follow protected-area rules |
| Greek foundations and myth | Cuma | Allow a half day for the acropolis, terraces and Sibyl's cave |
| Roman engineering | Piscina Mirabilis | Confirm whether restoration or local access rules affect visits |
| Thermal water | Pozzuoli and Baia | Check health, treatment and admission conditions before arrival |
| Local wine | Bagnoli, Pozzuoli and Monte di Procida | Arrange winery visits and a safe return plan |
Responsible and safe visiting
- ✦Read local civil-protection and access notices before a day around active volcanic ground. Do not enter closed craters, military land or restricted archaeological areas.
- ✦Marine parks are protected zones. Use licensed guides for Baia Sommersa and follow instructions about swimming, anchors, diving and photography.
- ✦Summer roads can be slow. If you are relying on public transport, build the day around Pozzuoli and one nearby site rather than promising every stop.
- ✦The caldera has little shade at open archaeological sites. Carry water, a hat and shoes that handle uneven ground.
- ✦For a wider walking, swimming and diving plan, continue to the Campania outdoors guide.