III.(Field Note) Campi FlegreiPhilip Samartzis
(Reading time, 20m23s)Preface
These essays were written over eight days in Campi Flegrei during June 2026.
Following my residency in Somma Vesuviana, I travelled west into the Campi Flegrei to continue my research into how communities inhabit landscapes shaped by instability and uncertainty. Although the two regions are closely connected, they suggest different ways of living with volcanic processes. In Campi Flegrei, towns, roads, archaeological sites and coastlines occupy a caldera that continues to rise and fall through successive cycles of bradyseism. Since 2005 the region has been in a prolonged phase of uplift accompanied by recurring earthquake swarms. During the weeks before my arrival, several stronger earthquakes had renewed local anxiety.
The bay provided an unexpected point of orientation. Ancient writers describe the emperor Caligula constructing a temporary bridge of boats between Pozzuoli and Baia. Elsewhere, Roman villas, harbours and baths now lie beneath the water. Mussel cultivation continues above submerged archaeological remains, while shifts in ground level alter the relationship between land and sea. The landscape brings different periods into close proximity without clearly separating them.
The essays trace conversations, field recordings and encounters across the caldera. They follow railway tunnels temporarily closed by volcanic gases, geothermal fields, archaeological parks, lakes, shorelines and the historic centres of Baia and Pozzuoli. My understanding developed through conversations with Tommaso Nudo, Emanuele Errante and Leandro Pisano as the landscape gradually revealed itself.
Over time, certain relationships became apparent. Geological processes were seldom encountered directly, becoming evident instead through altered coastlines, repaired buildings, interrupted journeys and conversations that shaped my reading of the landscape. By the end of my stay, Campi Flegrei had become more legible, though not necessarily more comprehensible.
Inside the Caldera
I first become aware of Baia before I arrive.
Somewhere beyond Naples I think I can smell sulphur. The scent appears briefly before disappearing again as the train continues west. I remain uncertain whether I have imagined it until Tommaso Nudo explains that the wind often carries volcanic gases across this part of the coast.
Earlier in the journey Tommaso remarks that people here rarely speak about the future. Living inside an active volcanic field, he suggests, has encouraged an acceptance of impermanence rather than certainty. The comment stays with me.
When the train reaches Baia, we stop before a large geological map mounted on the station platform. Tommaso traces the outline of the caldera with his finger. Lakes occupy ancient craters. The surrounding hills are volcanic cones. Towns, roads and vineyards extend across them almost continuously. Only then do I realise that I have not arrived in a town but inside a volcanic landscape.
The previous day a series of earthquakes had unsettled Campi Flegrei.
At Il Barbacane, a guest house built into the lower slopes of Fondi di Baia, the owner explains, through Tommaso, that the building has been engineered to withstand seismic activity. Reinforced concrete columns pass through every level of the structure. The main entrance also serves as an emergency exit, fitted with a horizontal push bar for rapid evacuation. None of these features is presented as unusual.
Outside the guest house, the afternoon heat settles heavily across the lower slopes of Fondi di Baia. Inside, the air-conditioning is kept deliberately frigid. Entering the guest house is a shock. Stepping back into the afternoon heat a short time later is another.
From the guest house, Fondi di Baia rises towards the Castello Aragonese. Vineyards, retaining walls, woodland and scattered houses occupy its slopes. It is difficult to know where the volcano ends and the landscape begins. Only the following morning, while recording, do I begin to understand that it is also shaping what I hear.
Shortly after sunrise I begin recording from the garden.
Woodland birds dominate the foreground while gulls occasionally pass overhead from the shoreline below. Somewhere beyond the ridge a dog barks continuously. The slopes of Fondi di Baia return each bark with a short slapback echo before it dissolves into the wider landscape. Sometime later in the day I learn that dogs are said to sense seismic activity well before people do.
Later I walk through Baia.
The town gradually reveals the geology from which it is built. The distinctive yellow volcanic tuff appears in walls, stairways, retaining structures and older buildings. Roman arches, vaults and fragments of masonry emerge between apartment blocks before disappearing again behind gardens and fences. Antiquity has not been separated from the contemporary town. It remains deeply embedded within it.
That afternoon I meet Emanuele Errante at the Monkey Bar. He suggests we spend the afternoon recording at Lago d'Averno. Earlier in the day I had read that Virgil located the entrance to the underworld there. The association returns as we leave Baia.
On the drive Emanuele recalls occasions when birds fell from the sky after entering pockets of volcanic gas. He mentions the story almost in passing, yet by the time we reach the shoreline I find myself listening to the lake rather differently. The water is completely still.
We record around the lake.
Wind moves through the reeds along the foreshore. Insects occupy the foreground. Voices occasionally carry across the water before disappearing again. In a nearby garden several plastic bottles mounted on poles slowly turn in the breeze, producing a light, hollow resonance before falling silent.
While recording, Emanuele points towards the mountain beyond the opposite shore. It appears settled within the landscape, softened by woodland and scrub. He tells me it is Monte Nuovo, a volcano that emerged during the eruption of 1538. Within a week cultivated land had become an entirely new mountain. Standing beside the lake, it is difficult to imagine the violence that suddenly brought it into being.
As we return to Baia the wind begins to rise again.
I think back to the smell on the train that morning, carried across the caldera long before I entered it. Over the course of a day the landscape has become more legible, though not necessarily more comprehensible. Its geology reveals itself only intermittently—through conversations, field recordings, fragments of history.
That night I fall asleep shivering in the cold air of the guest house.
Pressure
Emanuele collects me from the guest house shortly after half past five.
We leave Baia before the weekend traffic begins to build. The roads are almost empty.
We stop at a petrol station on the outskirts of Pozzuoli.
The espresso cups sit submerged in a stainless-steel tray filled with boiling water. They are almost too hot to hold. The cornetti are stale.
As we continue, the smell of sulphur becomes stronger. Yesterday it arrived only intermittently. This morning it settles across the road long before the geothermal fields become visible.
Our first destination is La Solfatara di Pozzuoli.
The crater has remained closed since the deaths of a family in 2017. We stop briefly outside the main entrance on Via Solfatara. A large gate blocks access.
Emanuele parks beside a nearby building site. We walk down the hill towards the crater.
From the roadside the geothermal basin opens before us. The crater floor is unexpectedly flat, a broad expanse of bleached ground enclosed by steep walls. Steam rises continuously from several vents across the basin. Fences, walkways, small buildings and monitoring equipment occupy the exposed ground.
We begin recording.
The fumaroles are immediately audible.
At first I mistake the sound for wind moving through woodland. Only after listening for several minutes does another quality emerge. It neither rises nor falls. It simply continues—a sustained release of pressure escaping from somewhere beneath the surface.
We continue towards Pisciarelli.
The road bends around exposed geothermal ground where steaming fissures cut through sulphur-encrusted rock beneath the crash barrier. Ochres, whites and pale yellows spread across the fractured surface. Steam catches the first sunlight before dissolving into the air. Only metres away, cars negotiate the bend without slowing.
We begin recording again.
The hiss is remarkably steady.
Listening more closely, smaller sounds begin to emerge. Gas escapes through fine cracks in irregular bursts. Water bubbles somewhere beneath the surface. Nearby, a pressurised hose produces an intermittent ticking sound that drifts in and out of the recording, introducing an irregular pulse against the otherwise continuous release of steam.
Further along the road we arrive at a sports complex bordering the geothermal field.
Adjacent to the football pitch, a fumarolic chimney rises from a paved courtyard.
Its surface is thick with rust, ochre and pale green mineral deposits. Steam rises steadily while water bubbles somewhere below the surface.
I place a directional microphone above the vent. Beneath the steam, a hollow subterranean boiling sound is audible.
About twenty metres away, a modest spectator stand borders the same pitch.
Moisture blackens the concrete terraces. Green paint has lifted from the steps in broad irregular patches, exposing coarse aggregate beneath. The white render has become chalky and brittle. Hairline cracks spread through the plaster. Rust stains the steel railings and light poles.
Beyond the perimeter fence opposite the stand, steam rises continuously from dense vegetation within the geothermal field. By now the morning has become noticeably hotter and insects occupy the foreground almost completely.
I make another recording from the top corner of the stand.
Only later, listening back, do I notice a dense low-frequency resonance beneath the insects that I had not perceived while recording.
We remain on site for around half an hour before the owner appears.
The ground is private property.
He tells us to leave.
As we pack the equipment he speaks with Emanuele about the recent earthquakes. The land has continued to rise during the present uplift phase, accompanied by recurring shallow earthquakes. Business has suffered. Parents have become reluctant to bring their children here.
From the sports complex we drive to the Archaeological Park of Baia. Our destination is the Tempio di Mercurio.
The archaeological park preserves the remains of a Roman thermal complex built into the volcanic hillside overlooking the bay. The baths, reservoirs and vaulted chambers extend across a series of terraces, their arrangement shaped by the geothermal landscape from which they emerged.
By the time we arrive, the heat has become difficult to separate from the place itself. It rises from the ground, gathers in the stone and settles against the body. In Baia heat is not only atmospheric.
Cracks, stains, fractures, mineral deposits and collapsed surfaces appear across walls and floors. Moisture darkens the masonry. The surfaces seem to have accumulated the effects of earthquakes, subsidence, damp and prolonged exposure.
Beside one of the paths, a fig tree descends through the roof of a ruined chamber. Its roots disappear into the ground above while its branches occupy the room below. For a moment it becomes difficult to determine whether the tree is growing upwards or downwards.
Immediately beyond, a narrow corridor leads into the domed chamber of the Tempio di Mercurio.
The chamber once formed part of the Roman thermal baths.
From outside there is little indication of what lies beyond.
Stepping through the passage, the space suddenly opens beneath a vast dome.
The chamber is unexpectedly cool. Moisture darkens the walls. Light falls through the oculus onto the shallow water that now occupies the subsided floor. Every surface appears marked by damp, mineral deposits and time.
I remain there for several minutes before setting up omnidirectional microphones.
At first, footsteps gather beneath the dome before returning from several directions at once. Conversations, birds, insects and distant traffic arrive unexpectedly amplified. Sounds from elsewhere in the archaeological park converge within the chamber. Emanuele drops a series of pebbles into the shallow water, allowing each to dissolve into the space before releasing the next. The chamber behaves almost like an architectural parabolic microphone.
The space reminds me of Stalker. Emanuele mentions Nostalghia as we begin talking about Tarkovsky’s films.
Outside, the walls become increasingly difficult to distinguish from the volcanic material from which they were built. Volcanic tuff, brick, mortar and plaster weather into adjoining surfaces. The buildings seem slowly to be returning to the geology that produced them.
At the park entrance, the insect song is almost overwhelming.
The oppressive heat settles across the hillside.
Below, the town appears still.
Pozzuoli
We are due to meet Tommaso outside Pozzuoli station shortly after eleven o’clock.
Emanuele receives a text message. The railway tunnel has been closed and Tommaso has been delayed. Trains have been suspended while passengers are transferred by bus.
Outside the station, minibuses move continuously through the confined entrance. Emanuele inches the car forward before pulling over again. There is nowhere to stop for more than a moment. Heat radiates from the surrounding concrete.
Tommaso arrives a short time later. As we drive towards the old town he explains that carbon dioxide from the volcanic system has been detected inside the railway tunnel.
Leaving the station, my attention returns to Monte Nuovo. A few days earlier I was standing on its opposite side above Lago d'Averno. From here it feels curiously close. Framed by the streets around the station, the landscape seems to fold in upon itself.
The Temple of Serapis lies below the surrounding town, its courtyards, walls and marble columns exposed within a large excavation. Outside the perimeter wall the harbour remains visible. Only a decade ago water still occupied much of the site.
Emanuele points towards the dark bands encircling the columns. Marine borings left by molluscs mark a former waterline. He describes the changes as another consequence of bradyseism. Most people assume the sea has receded. It is the land that has risen. For Emanuele, bradyseism is the Earth's breathing.
Beyond the archaeological site, entire buildings are enclosed by scaffolding. Temporary fencing narrows several streets. Fresh render sits beside exposed masonry. Cracks remain visible across walls and façades. The work is so widespread that it becomes difficult to tell where one project ends and another begins. Repair has become a permanent condition.
The streets narrow as we approach the harbour. Fishermen's houses descend towards the waterfront. Emanuele pauses beside a stone statue in a small square. Its features appear slightly bewildered. He explains that the figure represents Bishop Martín de León Cárdenas, though it is better known locally as Santo Mamozio. Local belief holds that every time the statue is moved, misfortune follows. After it was relocated during the 1960s, residents came to associate the evacuation of Rione Terra, repeated episodes of bradyseism and other hardships with its absence. Many believed the town's fortunes improved only after the statue was returned to its original position.
Fishing boats appear abandoned within a small basin below Rione Terra. The broad stone slipway now ends high above the water. Mudflats, reeds and shallow green pools occupy what was once navigable water. Some boats remain tethered while others sit stranded at awkward angles. The present phase of uplift has left this part of the harbour disconnected from the sea.
From the headland a grey beach extends along the shoreline. It had emerged only two years earlier. People swim between scattered rocks while others lie on towels spread across the sand. Already, it seems embedded within the town.
I make a recording overlooking the basin below Rione Terra. Evacuated in 1970 during an earlier period of bradyseism, the historic quarter continues to be restored. The sounds of construction filter through narrow streets between freshly rendered façades. Boisterous seagulls occupy the arm of a crane above the reconstruction, peering down towards me before lifting briefly into the air and settling again. Across the bay, marine traffic continues much as it always has.
Our final stop is the Anfiteatro Flavio, one of the largest surviving Roman amphitheatres in Italy. On arrival we discover it is closed on Tuesdays. Tommaso presses the intercom fixed to the wrought iron gate. The conversation is brief.
“There will be no access today.”
After Nature
I wake to the sound of thunder.
The previous evening a code yellow weather warning had been circulated across Campi Flegrei. These warnings are not unusual and rarely amount to much. I begin recording shortly afterwards.
For the next three hours thunder moves across the caldera at varying intensities. Apart from the occasional shower, little rain falls. At nine Emanuele collects me from the guest house.
The previous day we had arranged to film around Baia. Tommaso was due to meet us with a filmmaker documenting part of the fieldwork. The weather alters our plans, and we decide instead to return to the Tempio di Mercurio.
The archaeological park is empty.
We carry the equipment down to the Temple and begin setting up shortly after half past nine. By the time everything is in place the thunder has become less frequent. Birds, occasional traffic and church bells return between distant rumbles of thunder. For a short while it seems we have missed the storm.
Then the first droplets begin to fall. They arrive through the oculus and smaller openings distributed across the dome. The first flashes of lightning briefly illuminate the muted interior before disappearing again. Moments later the thunder arrives, reverberating through the chamber with renewed intensity.
I lower the recording level. Over the next hour I continue reducing it in small increments. Every adjustment seems sufficient until the chamber responds differently once more. Rain now enters from almost every direction. Water falls, gathers beneath ledges, seeps through the walls and emerges unexpectedly between courses of Roman brick.
The stone gradually darkens. Surfaces that had appeared dry only minutes earlier begin to glisten. Water gathers across the floor before finding the central grate. Around the recorder shallow pools slowly merge before disappearing beneath the metal walkway. For a short time, the Temple seems less like a ruin than a functioning bath once again.
What begins as individual droplets gradually becomes a dense wash of sound reverberating through the chamber at different intensities. Rain striking stone, standing water, Roman brick and flowing streams merges into a continuously shifting acoustic surface. Each time I lower the recording level the chamber grows louder.
During a brief lull Emanuele checks his phone. The railway line has flooded before Pozzuoli. Tommaso cancels our plans for the morning. We continue recording.
For close to an hour the storm reaches an intensity unlike anything I have previously recorded. The recorder becomes the only reliable measure of what is happening as the architecture responds to each burst of thunder.
By midday the storm begins to ease. We dismantle the equipment while rain continues to fall intermittently. A guard holding an umbrella appears briefly at the entrance to the Temple before turning away. At the ticket office we are told they had expected us to leave once the storm intensified. When we failed to appear, they sent someone to check on us.
Outside, much of Baia remains waterlogged. Water continues to run along the streets as people sweep pools of rain and rubbish away from shopfronts and entrances. Police vehicles move quickly through the town in different directions.
On the drive back to the guest house, Emanuele turns into the narrow lane descending the volcanic slope. He slows the car as we approach a section of road covered with debris. Only then do I recognise the house I had photographed the previous day. One of its retaining walls has collapsed onto the lane below. Behind it, layers of stone, earth and concrete that had remained concealed only hours earlier are exposed.
By evening the rain has cleared but the thunder remains. Shortly before eleven o’clock I begin another recording from the guest house. Apart from the thunder, the landscape is almost silent. Each roll seems to rise from within the caldera before gradually retreating across the Bay of Naples. Between them there is very little else to hear. After a day saturated with sound, the quiet feels unfamiliar. The thunder no longer sounds like weather. It sounds geological.
Fumaroles
We meet Michelangelo late in the afternoon at the harbour in Baia.
Our boat is a rigid inflatable fitted with a single outboard motor. Alongside our recording equipment we carry a bag of diving gear. Michelangelo remains at the helm. Leandro Pisano sits at the stern filming. Tommaso and Emanuele take seats amidships. I settle in the bow.
Shortly after four o'clock we leave the marina.
Beyond the breakwater the sea becomes noticeably rougher. The afternoon wind has begun to build. The inflatable rises and falls as we head south along the coast.
We pause briefly above the remains of Agrippina's fish ponds.
The engine falls silent and we drift for a short time. Below us, walls and fragments of masonry become visible beneath the surface before disappearing again with the movement of the boat.
Leandro remarks that Baia became the summer retreat of the Roman emperors. Villas, bathhouses and fish ponds once extended along much of this coastline. Their remains now lie beneath the surface, submerged through centuries of bradyseism.
The engine starts again and we continue south. The cliffs become more pronounced. Layers of pale volcanic tuff extend almost continuously along the shoreline. Above them, buildings occupy the cliff tops while occasional fragments of Roman masonry remain visible between vegetation and retaining walls.
After around fifteen minutes we reach the first recording site.
The water here is relatively shallow. Emanuele enters carrying a mask, snorkel and hydrophone. He already knows where the fissures lie beneath the cliffs. Locating them precisely is more difficult. The boat is held in position while Emanuele repeatedly disappears beneath the surface. Each time he returns he signals towards the boat before diving again.
Eventually he remains over one of them.
He floats above the opening holding the hydrophone just above the seabed. In the shallower water he is occasionally able to stand. I monitor the recording through headphones, listening for changes in microphone position as much as the recording itself. Even slight movement alters it. Emanuele shifts the hydrophone a few centimetres before holding it steady again.
Streams of bubbles pass continuously through the hydrophone, producing a fine crackling. From time to time the rubber hull becomes audible as the boat lifts with the swell. Fragments of conversation filter through the water before dissolving again beneath the bubbles. Passing boats briefly enter the recording before disappearing once more. My attention remains beneath the surface.
I pass the headphones to Michelangelo. He listens intently for a minute before handing them back. The recording reminds him of his night voyages, when the sea can sometimes be heard in a similar way.
We make several recordings before Emanuele climbs back into the boat. Michelangelo turns us towards the centre of the bay. Long rows of buoys pass quickly to our right, marking the mussel farms that occupy much of the water. Their regular grid is repeated throughout Campi Flegrei, in the volcanic lakes and along the coast.
Emanuele tells me that mussel cultivation has shaped this coastline for centuries. Nearby Cumae produced one of the earliest coins in southern Italy. One side carried the image of a mussel shell. I realise I have never really considered what might appear on the earliest coins. Somehow a mussel seems both improbable and entirely appropriate here.
Beyond the farms the shoreline begins to recede.
Vesuvius remains visible across the bay to my left. Away from the coastline the sea becomes rougher. The inflatable rises more heavily as speed is reduced before turning towards a solitary yellow buoy.
We are now floating near the centre of the submerged caldera. The largest submarine fumarole lies approximately fourteen metres below us. This time no one enters the water.
I lower two hydrophones over the side of the boat, spacing them several metres apart before allowing them to descend to a depth of around ten metres. Suspended beneath the boat, they drift gently with the swell while I continue monitoring the recording for changes in position and focus.
Plumes of bubbles rise continuously through the hydrophones. Thousands of individual bubbles remain clearly discernible, producing a dense crackling. The sound recalls the geothermal fields we recorded several days earlier. Pressure finding a way through fractured ground.
Waves lift the boat before falling heavily beneath us. Passing boats occasionally introduce a broad low-frequency pulse that occupies the same register as the bubbles, briefly flattening their complexity before gradually receding.
Above the surface, waves and passing boats continue across the bay. Through the headphones my attention remains beneath them.
For a short time, Vesuvius and the submerged caldera converge within the same field of attention.