Preparation for our Descent

View of the underground tunnel complex
View of the underground tunnel complex

A ‘Nekyia’ – descent to the underworld – was never undertaken without due preparation and ours is no exception. In Greek or Roman times a map was probably not given, but it might help us to explore this site to have an overview of what is hidden behind the hill.

A quick assessment of the extent of the tunnel system buried deep within a volcanic crater wall at Baia might make one pause for thought. The scale of engineering, through solid rock, simply to provide steam for a very tiny set of baths at the surface is out of all proportion. A sledgehammer to crack a nut. Nevertheless, this effort was a feat of ancient engineering that is unequalled anywhere else that we know of.

To give some idea in human terms, the number of steps to the Dividing of the Ways is about 195 steps. From there to the underground water source is a about a further 72 steps. A total of 267 steps.

Pause for thought

If the tunnels were dug to provide steam for the Roman baths, how did they know the steam was there?

How could they navigate 170 metres (558.4 feet) through solid rock, with no false turns?

Why didn’t whoever dug into the steam source not die instantly, either drowned or scalded?

Why was it necessary to include over 550 oil lamp niches in the walls?

Why are there multiple doors near the heat source and who used them?

Why is there a ‘Sanctuary’ area with bricked up doorways?

Why the complex twin return tunnels from the ‘Sanctuary’?

Why is there a passage leading up to the ‘Sanctuary’ from the far end of the water course?

Why was the ‘Sanctuary’ laboriously closed off with brickwork and the tunnels filled with soil?

These and many other questions will be explored as we meet the features.

Where was Doc Paget right and where was he wrong? We are now able to make some judgements, based on better information and more detailed research. Doc Paget worked using only the dim battery torches available in his day, and film cameras with expensive film and single-use flashbulbs.


At the Far End of the Great Antrum

Once we have travelled 124.5 metres (408.5 feet) down the Great Antrum, we will meet the complex features that we know exist down there.

Most of the names used are those that Doc Paget used in his publications. A few additional ones have been named by the team behind this website, such as Persephone’s Back Passage – a tribute to both Virgil’s Aeneid and Doc Paget’s earthy sense of humour.

Talking of earth, it is perplexing why there is so much soil in the deeper regions of the tunnels. We have explored the following possibilities:

  • The tunnels provided a convenient dumping place for when the Serino Aqueduct was dug. The aqueduct crosses over the Great Antrum. The top tunnels are carved out of solid rock and there are no known holes from above. A more detailed investigation may shed further light on this proposition.
  • A volcanic event caused a draught that blew the material in from outside. If you have ever tried to blow sand into a bottle, what will happen? Any material that was deposited in this way should show some grading of the material, heaviest pieces travelling a shorter distance than lighter ones. 
  • Inspection shows a jumble of heavier and lighter material, even in the farthest reaches. This suggests that it was brought in deliberately and placed there by human hand. If so, it was an enormous undertaking. Why do it?

This Post Has 6 Comments

  1. edward baker

    Dear Persephone Hades

    Thanks for your swift and courteous reply, which are superior to my intelligence l fear. Am I to understand that the sunrise would not have been visible prior to 79.
    Apologies for a stupid question, was just intrigued by comparisons to sites in other locations.
    Thanks again

    1. Persephone Hades

      Dear Edward,
      Vesuvius, seen from the restricted view from the ‘Grotto’ above the Great Antrum entrance would have been clearly visible before it blew its top in 79 AD. Vesuvius is outlined in red in the picture.
      The view to Vesuvius from the 'Grotto'.

      The sun rises behind Vesuvius at a somewhat oblique angle as dawn breaks on the equinoctes. The sun does not rise vertically. As it rises, it appears to move to the south. All one could really say is that at dawn Vesuvius would be silhouetted dramatically on the horizon. As the tunnel and grotto above it are aligned to Vesuvius, going into the hillside at an angle to it, it seems to me unlikely that this was pure accident. If the site was used as part of the Greek Mystery initiations, perhaps candidates were led to view the sunrise before their descent. There is a tunnel, now blocked, that leads behind the Tholos. This tunnel and blockage can be observed from a passage that leads from the bottom of the South Tank, a feature inside the hill.
      Note the lamp niche in the left hand wall.
      The passage from the South Tank leading to the 'Grotto'.

  2. Edward Baker

    “Netherworld” refers to the alignment of the entry shaft and speculates that the building date could be established by computer work. Is the tunnel aligned significantly and if so, has that been tried?


    1. Persephone Hades

      The alignment of the Great Antrum, the entry shaft, looks directly at the equinoctial sunrise behind Vesuvius (of course it had not blown its top when the tunnels were made. The major eruption was in 79 AD). This was not something Robert Temple had recognised and he was surprised and delighted when I told him. This alignment, being more or less due east, has not changed significantly in the past 2,000 years or so and regrettably will not help us date the tunnels’ date.

  3. Jiri Branzovsky

    is the Oracle of the Dead publically opened museum please?
    I dream visiting this place for a year already…
    thanks, kind regards, Jiří

    1. antrum

      Hi Jiri,

      There is no public access to the tunnel system at Baia. The tunnels are too narrow and dangerous to allow this. Two people cannot pass in the tunnels. You can see the entrance only.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.