The Triplet Rooms

The buildings that sit on the terrace against the cliff are the oldest unearthed at Baia and they follow the cliff line. Later modifications divided up the space on the hillside according to another orientation – to better face the Bay of Baia and perhaps to allow the volcano of Vesuvius to provide a backdrop, as is seen at Taormina in Sicily where the theatre has the volcano Etna as its dramatic central backdrop.

Another tunnel?

The central topic of this website is all about tunnels and whether they either have a ritual purpose or are completely mundane steam channels for some Roman baths.

We might also wish to take an interest in any other parts of the surviving older terrace. to see if there are any other tunnels. We shall attempt to do just that.

What we are about to explore is a set of three rooms, named by this website as “The Triplet”, set underground and relatively deeply into the hillside. In other words, in solid rock.


Sweep across the picture above to see traces of buildings aligned on the more ancient orientation. What is of interest on this page is indicated by the tiny horizontal line, the last on the right of the picture.


“By descending along the narrow and picturesque lateral ramp on the north side of the hemicycle one reaches, through a long narrow corridor receiving light and air through ancient spy-holes, some subterranean rooms cut out into the thickness of the tufa. They show intersecting damp-preventing vaults, paintings on a smooth red and white background, and were probably used as a secret devotional resort of some slave and freedmen religious association of oriental origin, who were employed in the thermae.” Amedeo Maiuri, The Phlegraean Fields (Campi Flegrei), English edition.

The religious association of “oriental origin” that Maiuri had in mind could well be have been Christianity, St Paul having first landed nearby at Pozzuoli.

However, Orphism is also a likely candidate, linked as it is to the underworld. Orpheus features in at least four prominent paintings in the early Christian catacombs of Rome, so perhaps we are talking about the same thing.

Many other cults were also tolerated in Roman times, with Mithras being close to Christianity in the number of its devotees among the Roman troops. Mithras, like Isis before him and Jesus after him, had his official birthday on 25th December.

The Site Plan

Plan modified from the site signage at the Archaeological Park
Plan derived from the site signage at the Archaeological Park

The Plaster Room

Readers will forgive a brief diversion into a room that has been nicknamed The Plaster Room before descending yet again into hillside to explore the three rooms that comprise the Triplet. 

We are exploring here first, not only because of the fine Roman plasterwork on the ceiling, but because this room betrays the former presence of a stairway leading down to The Triplet, and because it obviously predates the construction of Sosandra, the curved nymphaeum with the small circular pool, which dominates this area of the Archaeological Park of Baia.

The Plaster Room with its fine ceiling
The Plaster Room with its fine ceiling
The entrance to the Plaster Room
The entrance to the Plaster Room

Several things can be observed in this room. Firstly, the end wall and the circular plaster cartouche on the ceiling has been brutally cut across during the building of the side wall of Sosandra bounding the steps the other side.

Secondly, the plaster is going up at the far end on the right. This is because originally there was an arched doorway there.

The left wall at the end of the painted room shows where the stairs once descended to a lower level.

The right wall at the end of the painted room shows where the original entrance was. This is the wall that is on the same orientation as the other ancient buildings on the terrace against the cliff.

The original entrance to the stairway was here. Just a few slight traces of the original archway can be seen in the exterior brickwork.

Approaching the Triplet

Having established that in a previous era, before the nymphaeum called Sosandra was built, there was a staircase leading down, through the Plaster Room, we can now descend the external stairs at the side of Sosandra and have a look.

Descending the external steps to The Triplet.

The transition curves from the orientation of Sosandra to the angle of the more ancient buildings.

A close-up of the curved tunnel to The Triplet.

Looking up shows where the old stairs once descended.

Almost there…

Before we enter The Triplet, we encounter an immense quantity of soil and rubble, very similar if not identical, to the material within the tunnel complex that has been the subject of enquiry so far on this website.

“Entry is from the rock-hewn stairway mentioned previously, at a point some eleven feet below ground. For the first few feet the tunnel is lined with masonry, then it is cut in the solid rock.… The passage is at least four feet wide and more than six feet high.”

Doc Paget – “In the Footsteps of Orpheus”

Just before we enter The Triplet we encounter a side feature with an avalanche of soil* we shall leave for now, and continue into The Triplet…

Looking back the way we came in, shows Andrew Gough, who was enlisted as ‘expert’ in Bruce Burgess’s ‘Forbidden History’ film, after Robert Temple had declined to be involved.

*It is believed by Peter Knight that this debris was thrown down the vertical shaft (now closed off somehow on the surface) and may well be the detritus from tunnelling of the Serino aqueduct that is cut through the hill above and very close to this point. Similarly, the fill blocking the secret tunnel in The Triplet, the Great Antrum complex and many other  tunnels in and around the upper terraces of this archaeological site.

Triplet Central

“We talked with the custodian and got him to show us the three rooms under Sosandra, which are illuminated and open to the public. Like all the remainder of the argillae, these were converted by the Romans to other uses when Section III (Sosandra) was built. But they still give the impression of having been used by a religious community.”

Doc Paget – “In the Footsteps of Orpheus”

The rooms that form the Triplet are not illuminated today, but they were until recently open to the public. It seems the débris was never fully removed after Maiuri first excavated here in 1956-58.

From this view, there are rooms to the left and the right – Triplet South and Triplet North. 

A Plan of The Triplet

We have entered the central triplet from the entrance shown at the top right of this plan.

The triplet its and associated features represent a complex arrangement of rooms and tunnels that is hard to understand. The three rooms are buried underground, with shafts to daylight in North Triplet and South Triplet that completely dominates those rooms and a different style of shaft in Triplet Central. Associated with the rooms is a secret room and a tunnel leading deep into the hillside. Further exploration would be necessary to gain anywhere near a complete understanding of the triplet. These rooms are aligned on the ancient terrace line of the buildings further to the south and it would be logical for them to be associated with them, rather than the later buildings of Sosandra which are oriented quite differently.

The room is bare, with plaster covered walls and simple painting. We cannot help but see the battered hole into the secret room at the lower right of the room. This really was a secret room, because it is a room with no door.

The Secret Room

“Behind the break in the west wall of the central triplet room is a small irregular chamber roughly 2.3 x 2.8 metres, (7½ x 9 feet) carved out of solid rock. A rubble wall divides it from the central triplet.

The only access to this room in Roman times would appear to have been from a tunnel above, which sits precariously halfway across one side of the secret room. The roof of the secret room rises at the back to allow enough headroom to access the tunnel into the cliff behind. In the back wall of the secret room there are traces of carving into the tufa suggesting an abandoned plan of some kind.”

Doc Paget – “In the Footsteps of Orpheus”

Within triplet central, if we are to step back a little and look up, we see the entrance to a tunnel. 

For once there is no suggestion that this has anything to do with steam heating a Roman bath. Its purpose is unknown, but there is surely something very unusual going on in this room.

Was it to listen to the occupants of Triplet Central? Was it to make eerie noises through the wall? Doc Paget thought and said so.

Once inside the secret room, we can look back at the battered hole we came in through. The secret tunnel runs halfway over the top of the secret room.

This thick front wall into the room was made out of cemented rubble and originally had no doorway. all the other three walls are carved out of solid rock, so no doors there either.

How did people enter the secret room? The only way was down from that slot which we can see above.

The Tunnel

“In the west wall, in the bottom right hand corner is a hole leading to a small room at the rear some 6 feet square. In the west wall of this, high up in the north corner, is a tunnel which runs westwards for an unknown distance as it is blocked by earth.

Returning to the central chamber we see high up in the north corner another tunnel which has been explored for 150 feet to where it is blocked by an earth fall.”

Doc Paget – “In the Footsteps of Orpheus”

Doc Paget’s account in his book is garbled. The two tunnels described by Doc Paget are, in fact, one and the same tunnel.

The first view shows the narrow shelf running partially above the secret room, looking into the tunnel into the hillside.

The second view is looking back towards Triplet Central.

Doc’s statement that these rooms were once illuminated is confirmed by the light fitting that still hangs in the tunnel, complete with its 1950s twisted wiring. 

The start of the secret tunnel is at an entrance that today appears high up within Triplet Central. It is a mystery as to why it appears to hang in mid-air like this.

The picture shows the start of the tunnel viewed from Trip Central.

The black spot on the roof is a bat, hanging upside down in the tunnel.

The Secret Tunnel

The tunnel is blocked some distance into the hillside by a large quantity of soil which has the appearance of sloping up from ground level to the roof at about 30º. This soil has been undisturbed for some time and some beautiful white crystals have formed on the surface, to which the camera cannot do justice. . It is suspected that this fill may have come from somewhere above.

Who, Why and When?

This was no steam channel for a Roman bath. Not much more can be said about this tunnel, except that it appears that its far end has never been investigated. Where does it lead? Who used it to sneak into the Secret Room, or pass over the Central Triplet? Answers must await another day. It’s possible it might intersect the tunnel from the Elysian Portal to the Dividing of the Ways, but this is pure speculation.

North Triplet

Dominating almost the entire east face of the North Triplet’s wall is a curious tapering shaft which exits to daylight behind a modern grille at the top of some open air steps.

The facing west wall and adjacent north wall have arched niches. Both have damage in the wall which suggests that a statue or other feature has been robbed.

“The room to the north has been reduced in size and given a cruciform plan. In the walls are statue niches. Who knows if this was not a meeting place for the early Christians?”

Doc Paget – “In the Footsteps of Orpheus”

The plan isn’t really cruciform, it is roughly square with a recessed niche in two adjacent walls.

The ceiling and niche opposite the tapering shaft to daylight

The ceiling and niche opposite the tapering shaft

The entrance to the Central Triplet
The entrance connecting to the Central Triplet
Another look at the curious tapered shaft
Another look at the curious tapered shaft

The fact that the room was plastered and painted and had niches containing objects of some kind suggests these rooms were for ritual use.

The tapering shaft to daylight
The tapering shaft to daylight
The niche with missing feature
The niche opposite the tapered shaft
The niche opposing the entrance door
The niche opposite the entrance door

South Triplet

South Triplet is a circular room which has clearly been adapted to a Roman bath house – a sudatorium or sweat room. The floor has been sunken down and broken suspensurae (hypocaust footings) scatter the floor. As with the north triplet, this room is also dominated by a tapering shaft to daylight.

Two crudely-formed niches adorn the south and west quadrants, in a similar way to those seen in North Triplet.

From the top of the shaft into the South Triplet
From the top of the shaft, looking into the South Triplet


The tapered shaft to daylight
The tapered shaft to daylight
Looking through South Triplet's doorway to the niche opposite
Looking through South Triplet’s doorway to the niche opposite

South Triplet’s niches

The small pillars on the floor are suspensurae, supports for the floor which was once heated from underneath. The steam inlet for the bath is from a small feature accessed from the entrance tunnel to The Triplet rooms, not from a tunnel into the hillside.

This niche, which is directly opposite the entrance to the room, has a crudely-formed arch at its top. The side walls forming the niche taper towards the back wall, as if radiating from the centre of the room. It would seem that this must have been intentional, but on close inspection it looks unusual and peculiar as we are used to seeing well-formed niches with walls parallel to each other. Perhaps it was meant to be viewed from the exact centre of the room?

The niche opposite the tapered shaft
The niche opposite the tapered shaft

A robber’s hole is deeply carved into the rear of the recessed niche. They found nothing, it is all solid original rock.

Doc Paget made a statement in his book ‘In the Footsteps of Orpheus’ as follows:

“All these rooms were much reduced in size at the reconstruction, as all the walls ring hollow when struck, showing there is hollow space behind.”

Doc Paget – “In the Footsteps of Orpheus”

Doc, surprisingly, makes no mention of the deeply carved recess in the back of this niche, which makes one wonder if someone had read Doc’s statement about hollow walls and decided to dig after reading his book.

Striking the walls possibly gives off a reverberation – an echo –that may have suggested to Doc that the walls are hollow.

Central Triplet Revisited

To describe the rest of the features of The Triplet, which are truly perplexing and difficult to describe, it is necessary to revisit the Central Triplet. As has been described further up the page, a tunnel into the hill, carved into sold bare rock, starts above the Central Triplet. It runs into the hills over a room that was hidden and had no entrance except from the tunnel above it – the Secret Room.

What this section attempts to describe, and it is going to be very difficult to do so, is what is happening in the opposite direction – around the entrance area. Firstly, we can look more closely at the situation in and above the Central Triplet.

We have arrived into the Central Triplet from the entrance on the right in this picture. A drift of soil that we have just climbed over is visible on the floor.

Above us we can see a square shaft, projecting upwards.

Looking up, back into the tunnel into the hillside, we can see where the plastered area of the room gives way to bare carved rock.

Plaster is missing in a band to our left, that might suggest that a platform was once here – perhaps made of perishable wood.

Turning around to look in the opposite direction, the missing band in the plaster is now on our right as we look above us.

We are now confronted with a tunnel or shaft that is no longer horizontal, but sloping somewhat sharply upwards.

Standing a little further back, we can look at the entrance with its cascade of soil coming out of somewhere on the right.

Above us is the sloping shaft again. We might just be able to observe some kind of ‘mouse’ hole on the right above the missing plaster.

A plank that was once laid across from the tunnel to the sloping shaft above the entrance tunnel, which we can see below in the Central Triplet room.

The plank was sloping significantly downward indicating that tunnel and the shaft it was leading to are not the same feature. They are two separate tunnels.

Halfway up the sloping shaft is this ‘mouse-hole’ on the right, which extends horizontally to a vertical shaft with footholds.

The unexplored vertical shaft with footholds is where the huge fall of soil is spilling out into the entrance tunnel. It has another tunnel on the right which exits at the ‘mouse-hole’.

Looking up the vertical shaft with footholds. The footholds are almost invisible in this picture, but can be seen faintly at the ’10 o’clock’ position.

Filming in The Triplet

In 2015, film-maker Bruce Burgess, known for his conspiracy and fringe theory topics such as Bigfoot, the Bermuda Triangle and alien abductions, was granted permission to film in the tunnels. 

The film formed part of the series called ‘Forbidden History’. In this episode they went in search of the Oracle of the Dead. The team chose the South Triplet to stage a mock séance of the Sybil.

Andrew Gough, seated in white, was the film’s historical ‘expert’. Celebrity Jamie Theakston was employed as the ‘front man’. Director Bruce Burgess is in the blue shirt, while local student Noemi Cuomo in a red dress serves as the spell-bound Sybil.

The film team eventually chose the pure Roman Augustan troop tunnel running from Lake Avernus to Lake Fusaro as their preferred Greek Oracle of the Dead site. It certainly isn’t the right choice, but never let the truth get in the way of a good story.

Triplet Reprise

While attempting to make things clearer, perhaps this diagram also conveys the complexity of this underground system. Keep in your mind that all the dark red areas are floors. This might make it easier to focus upon the complete structure.

  • The approach tunnel

    This once descended from some internal stairs from an entrance that, in part, still survives – especially visible in the angle of the plaster above the entrance above in the Plaster Room, the profile of the opposite wall of the Plaster Wall and the sloping descent in the approach tunnel, visible in the roof.
  • The Vertical Shaft 

    Just before the entrance to the three rooms is a drift of soil that has dropped down a tubular vertical shaft with footholds.

    A horizontal tunnel joins this tubular shaft to the shaft ascending from the Central Triplet.

    Over the drift of soil at the foot of the tubular shaft is a carved cavity with water which is likely to be associated with the South Triplet’s conversion to a hot room.
  • The Central Triplet


    This room is devoid of features other than the vertical shaft in its north-eastern corner which breaks a tunnel. The tunnel leads horizontally into the hillside, having first traversed over the Secret Room.

    In the opposite direction, another tunnel tapers upwards towards daylight, although the light is today blocked at its top end. It has a horizontal side tunnel, the ‘Mouse hole’, which connects this shaft with the tubular Vertical Shaft.

  • The Secret Room

    Where the wall has settled and cracked in the Central Triplet, we can easily see today that a room, carved into solid rock, is concealed behind it.

    Robbers have broken through into the Secret Room, so we can see that a rubble and cement wall divided the Secret Room from the Central Triplet.

  • The North Triplet

    The room contains two statue niches and little else, except for a huge shaft dominating the room which tapers upwards to daylight. No purpose has been assigned to this room. Amedeo Mauiri suspected religious use of some kind to all three Triplet rooms.
  • The South Triplet

    The space is arranged in a similar way to Triplet North, except that it is circular and clearly been converted to a hot bath room, as it has the supports for a heated room. The floor has been lowered to accommodate this.

    As with the North Triplet, it has two statue niches and again is dominated by a tapering shaft to daylight.

The Shaft Tops

In this photograph we are peering through one wall, complete with cobwebs, past another wall, to a third wall through which we can see the top of the shaft from the South Triplet. What exactly is going on here is not known. The shafts do not seem to be convenient chutes for goods to be slid down and anyway they taper the wrong way to be funnels. They may be to allow light in and/or vapours to escape.

A view between the
inner pair of walls

A view between the
outer pair of walls

Light Enters
South Triplet here

Light enters
North Triplet here