Even though the man who has tramped all around the cellars, wells, canals and whatnot underneath Valletta’s streets and buildings keeps saying there are no mysteries to be discovered, people are still fascinated by the subject.

On Notte Bianca, in just seven hours, no fewer than 5,000 people roamed around the cellars of the Auberge de Castille and into a wartime shelter there, to come up on the other side of the road, at the Auberge d’Italie.

On Wednesday, an appreciative crowd gathered in the cellar of the same Auberge de Castille for the launch of a book, Subterranean Valletta, by Edward Said, published by Fondazzjoni Patrimonju Malti (back publishing quality books about Malta’s cultural heritage after a hiatus of some years, due, we were told, to some “technical issues”).

At the end of the presentation, the guests followed the same path – down some steps into the shelter, steps slippery with water, corridors awash with rainwater, down more steps and up into the Auberge d’Italie.

Judge Giovanni Bonello, introducing the book, made two points.

We have, he said, come full circle. In the 17th century, Antonio Bosio had published a book, Roma Sotterranea, that remained the standard text, the first comprehensive account, of what lay underneath Rome’s streets and buildings: the catacombs, the dungeons, etc.

Bosio had been born in Malta and had a Maltese connection. And he was the Christopher Columbus of subterranean Rome.

This book by Edward Said includes many pen drawings of the underground system of Valletta drawn by Romano Carapecchia.

This has become very much a Carapecchia year, said Judge Bonello. The church of St Catherine of Italy, built by him, has been wonderfully restored; the Cappella Ardente at St John’s Cathedral, also by Carapecchia, has also been restored and Mepa has just approved the restoration of the Carapecchia façade of the Manoel Theatre.

And now, for the first time, a book has been published that shows many of his drawings of the wells, reservoirs, cisterns, etc., underneath Valletta.

After all, Carapecchia himself was primarily a water engineer and he had been brought to Malta to assess the provision of water in a fortified and enclosed city in the event of a siege.

Mr Said entertained the audience with a story how his fame regarding underground Valletta had led a woman from the area known as Arcipierku to call him to go and see if he could sort out her drainage problem!

He paid homage to the many unknown and unsung heroes whose work takes them deep into the tunnels underneath Valletta, at great danger to their health, and how these people (especially Maltacom workers) are incredibly knowledgeable about the tunnels and connections to be found there.

Mr Said explained that the arches surrounding the audience, the cellars of the Auberge de Castille, were most likely among the very first things to be constructed after the Great Siege, since the normal practice of those days ordained that the stone for a building was quarried on the site of the building itself.

Today’s heroes of underground Valletta can count as their worthy predecessors those who dug out the ditches and the tunnels, people who were praised by Laparelli – the Pope’s own architect – for getting on with a very hard job with alacrity and with the minimum of fuss.