In the second of this series of pictures looking at the hillside site of the excavations you can see a small plateau at the extreme top left. This is part of the site of Caesar’s Villa at Baia, accessed from the Via Bellavista, the road that runs across the back of the site, following the ridge of the hill towards Bacoli.

Regards, Peter Knight.

During my years as a volunteer diver with the amateur group G.A.N., we were once asked to assist the group in the exploration of a nearby tunnel system that was adjacent to the road in Lucrino since they lacked any breathing apparatus that would allow them to safely traverse the tunnels without suffering from the effects of any gases that were present. We cheerfully complied, but as a precautionary measure we each wore our scuba tank and regulator requiring only one removal to get through a tight restriction. A closed circuit oxygen rebreather would have certainly been a more comfortable choice than the heavy steel scuba tank, but we didn’t have any with us at the time.

On one wall near the entrance, there was an inscription attributing the construction of the tunnel to the emperor Hadrian. Most of the inscription was crumbling which required repeated attempts with different lighting angles to properly photograph. There were heavy deposits of sulphur crystals that obscured much of the inscription chiseled into the stone wall. A subsequent excursion was made by the team using aluminum foil to make a non-destructive “cast” of sorts to fully decipher the text. Half way down the tunnel we encountered a short section of aqueduct specus (mix of flat red tile for the pointed arch and walls of opus reticulatum only 1 meter in height) that is found in acqueduct structures but it seemed odd to find it embedded in this dry section of carved rock.

Beyond this restriction the tunnel ceiling extended ahead while the floor sloped downward with deep sifted dirt on the floor that ended in a flooded section approximately 5 meters across. The water was less than a meter in depth and almost a bright yellow in color. There was a strong hydrogen sulfide odor that encouraged us to keep using our regulators. We wedged ourselves between the narrow walls to cross to the opposite side without getting our feet wet. There the floor rose again at a steep angle coming back up to the top of the ceiling where the walking height section of the tunnel ended abruptly with a left turn. It only extended another 3 meters or so with visible traces of the last stone cutting tools’ marks in the dead end wall of the tunnel. We didn’t take accurate measurements on that exploratory trip, but I believe the section of tunnel that we were in was only about 60 meters long. The high level of humidity in the tunnel fogged the filters and lenses of our cameras, including the underwater Nikonos I had brought with me so that we were unable to get any footage of the most interesting portions of the tunnel.

The only pictures we were able to get were those of the inscription near the entrance which had plenty of outside air and normal humidity levels. In my return visits to the area in 1998, 2004, 2006 and 2012, I was unable to locate the entrance to this tunnel but I have often wondered what this incomplete project was intended for.Some of the residential properties in the surrounding hills that I have been in were built upon older ruins which have tunnels underneath them, some of which now are used as wine cellars or storage. It would be interesting to explore and map them all to gain a comprehensive view of the complete underground network in this area.

The story of noxious gas in the tunnels has persisted since it was first opened, probably coming originally from Amedeo Maiuri, who forbade his workmen to venture into the tunnel very far on the grounds of noxious gases. When first opened the general temperature, certainly down at the River Styx, was a lot hotter than it is today. When Paget entered in the 1960s he could see where the excavators’ footprints ended, a short way in. Noxious gas still remains as the official excuse for discouraging people from entering. If you had written for official permission to enter it would probably have been denied for this reason.

It could well be dangerous down there for other reasons, such as burial by the soil that now fills parts of the tunnels, deliberately put there by the Romans to seal the place off. Temple and Baigent have been any denied further official access, in spite of repeated requests. The powers that be don’t want anyone going in there.

Any miner will tell you that it is not possible to ventilate an underground system unless you have one entrance for new air to come in and one for the old air to go out of. Yet this place has just one that we know about, worked by sucking cool new air in along the floor while stale hot air went overhead. There was an inner circulation system that worked before the Romans blocked off the passage to the sanctuary. The hottest air is at the lowest point of the complex. This rose up to sanctuary level, and then further up into a tunnel that met at the 400′ point. From here it went out along the ceiling of the main entrance tunnel. The Romans blocked off the sanctuary tunnel and it remains blocked today. In spite of this it is possible to breathe in there. The tunnels have a lot less height today, through crystalline deposits settling on the floor to the depth of about 2′ 6″, 0.75 metres.