Stufe di Nerone in Pozzuoli: the Forgotten Roman Baths of the Campi Flegrei

The breath of the earth beneath the Campi Flegrei

A few kilometres from the centre of Pozzuoli, between Lake Averno and Monte Nuovo, the ground exhales steam at temperatures exceeding 90°C. The Stufe di Nerone are one of Italy's most impressive thermal phenomena, a place where the volcanic activity of the Campi Flegrei manifests itself directly, tangibly, almost unsettlingly. The name is evocative but imprecise: it was not Nero who discovered these natural caves, but the Romans of the republican era, who used them as sudatoria — steam baths avant la lettre — as far back as the second century BC.

The Campi Flegrei, from the Greek phlegraios (burning), form a vast active volcanic area extending to the west of Naples. The phenomenon of bradyseism — the slow rise and fall of the ground — has shaped this territory for millennia, creating lakes, craters, thermal springs, and fumaroles. The Stufe di Nerone are one expression of this subterranean energy: rainwater seeps into the ground, is heated by the magma, and rises again as steam through cracks in the rock.

The caves and the steam

The site comprises several natural caves carved into the tufa, inside which steam emerges at temperatures ranging from 50°C to 90°C. The atmosphere is dense, humid, almost unbreathable in the deeper cavities. The Romans had organised them into a thermal route that moved gradually from cooler to hotter environments, following a codified ritual that anticipated the modern sauna by centuries.

The thermal water that emerges at the surface has a temperature of about 82°C and a sulphurous-alkaline composition, rich in potassium, sodium, and silica. The therapeutic properties have been known since antiquity: Pliny the Elder recommended them for skin and bone conditions, and in the Middle Ages the site was frequented by those suffering from rheumatism and arthritis. The thermal muds of the Campi Flegrei, used in Roman baths, are still considered among the most effective in Europe.

The history of the site

The Roman thermal complex, of which foundations and wall fragments remain, was part of a larger system that included the baths of Baia — the greatest thermal centre of the ancient world. In the imperial era, the entire Phlegraean coast from Pozzuoli to Miseno was dotted with villas, thermal establishments, and ports. The Stufe di Nerone were probably frequented by the local middle class, while the nobility preferred the baths of Baia, more luxurious and fashionable.

Visiting the Stufe today

Access and current state

The Stufe di Nerone today house a private thermal centre (coordinates 40.8356°N, 14.0783°E), offering access to the steam grottos, thermal pools, and wellness treatments at accessible prices. The daily entrance includes use of the outdoor and indoor pools, the natural grottos, and the relaxation areas. It is advisable to check current opening hours and prices before visiting, as the centre has had periods of closure and reopening.

How to get there

The site is located along Via Stufe di Nerone, about 2 km from the Cumana railway station at Lucrino. From Naples, the Cumana line (from Montesanto) reaches Lucrino in about 25 minutes. By car, take the Naples ring road towards Pozzuoli, exit at Arco Felice. Parking is available at the facility.

When to go

The springs are accessible year-round, but the best months are the intermediate ones: March–May and September–November. Summer is hot and the experience of 90°C steam can become excessive. Winter offers an intense experience: the contrast between cool air and boiling steam is at its peak, and visitor numbers are minimal.

What to bring

• Swimming costume and towel (also available to rent on site)
• Non-slip sandals for the wet areas
• A water bottle: hydration is essential in the steam grottos
• A change of clothes: you will emerge completely drenched in sweat
• Avoid metal jewellery: sulphurous steam blackens it

Precautions in the grottos

The steam grottos are not suitable for everyone. Those with heart conditions, high blood pressure, or claustrophobia should avoid them. Time spent in the hottest cavities should not exceed 10–15 minutes. Always listen to your body: if you feel dizzy, nauseous, or short of breath, leave immediately. Young children should not enter the hotter grottos.

The Campi Flegrei beyond the springs

The Stufe di Nerone are just one stop on a Phlegraean itinerary that deserves at least two days. The Archaeological Park of Baia, with its submerged structures visible from glass-bottomed boats, is a unique experience in the world. The Solfatara of Pozzuoli — an active volcanic crater where the ground bubbles and sulphur vapours rise from fumaroles — is a staggering natural spectacle. Lake Averno, which the Romans believed to be the entrance to the Underworld, is a volcanic lake ringed by lush vegetation, ideal for a contemplative walk.

For food, Pozzuoli offers an excellent gastronomic scene: fresh fish from the gulf, served in restaurants along the port, is among the finest in Campania. At Da Ciccio on the waterfront, the mixed fried fish and sea urchin spaghetti make for an unforgettable lunch.

Where myth meets geology

The Campi Flegrei is a place where mythology and science tell the same story in different words. The Romans saw gods and the underworld; we see magma, faults, and hydrothermal phenomena. But the physical experience — the enveloping steam, the heat that penetrates to the bone, the primordial smell of sulphur — remains identical to that of two thousand years ago. The Stufe di Nerone are a doorway into the deep time of the Earth, open and steaming at the heart of the most alive city in the Mediterranean.