Napoli Underground - Urban speleology
A Photo Tour of the Marvels Beneath the
A Photo Tour of the Marvels Beneath the City of Naples, Italy

This is a quick look at a typical sampling of the wonders that honeycomb the earth beneath the ancient city of Naples, Italy. The durable and easily worked 'tuffo' or yellow tuff sandstone was ideal for digging deep aqueducts from springs in the outlying mountains down into the city. The Greeks first did this some 2,500 years ago, and over the centuries other aqueducts were dug in the sturdy tuff. This wonderful sandstone made of hardened expelled volcanic ash and lava over the millennia is also a perfect construction material, and huge palaces and villas were built from large blocks of this wonder stone quarried from ever widening bottle shaped cavities beneath them. The sloping sides of the bottle shaped quarried void maintained the structural integrity of the ground beneath the huge buildings. The cavities were then cleverly used as huge water reservoirs some 30 to 40 meters below ground. Diversionary tunnels were dug from the cavities to aqueducts filling the reservoirs, which were lined with lime. This provided a ready supply of fresh water to the buildings above. Other well shafts were dug to allow access to the water reservoirs by the public within the early walled city.

The photos below are typical of what our Naples urban speleologists continue to find year after year. Catacombs were created "in negativo" that is to say support columns and chambers as well as burial crypts were carved into solid tuf creating rooms and chambers that stretched into thousands of cubic meters of space. The voids, cavities, tunnels, aqueducts, and passageways conservatively occupy an area beneath modern day Naples equal to three times the size of the Vatican. Only a small percentage of the maze has been explored and mapped!

So, let's take a quick look at photos, recently re-discovered in the incredible stacked up files of senior president emeritus of the Italian Southern Speleological Society, Engineer Clemente Esposito. Photos that have been taken over his more than 50 years of exploring the mysterious marvel called the "Sottosuolo" of Bella Napoli.

Larry Ray

by Napoli Underground

Earliest Examples Dating from Paleochristian Times

An example of digging "in negativo" into the solid tuff, seen in the intricate construction of the paleochristian San Gaudioso Catacomb. It is typical of those dating between the 2nd and 9th century A.D. This one is accessed from a small passageway in a 17th century church!

Clemente is among the first to discover Greek Hypogea similar to this one . . . burial crypts dug deeply into the yellow tuf which still have amazingly intact frescos and decorations dating from paleochristian times.

Excavations by the famed Naples Archeological Museum have revealed an entire Greco-Roman city street. This is Roman construction built over Greek ruins. This is a bakery oven, part of an entire street lined with similar shops which lies beneath the San Lorenzo church in the ancient original historic city center. Greeks built walls by stacking carefully fitting stones. Romans used cement, creating masonry walls with the characteristic diagonal 'diamond' shaped tuff block masonry.

The Aqueducts from 2,500 years ago

The first aqueducts were dug by the Greeks some 2,500 years ago. This particular section is quite large compared to the snug fit of many we now use to navigate beneath the city. The pick marks from Greek slave laborers are still clearly visible today.

This is a typical example of the immense cavities that were used as reservoirs, complete with access sidewalks for maintenance. These snake for miles beneath Naples.

And here's how we drop in for a visit and a look around! Old well shafts on the surface belie what is below. Note the mountain of debris, typical of what clogs up and blocks many of the cavities and accessways. Unfortunately the surface opening shafts are simply considered to be the world's largest trash bin in the minds many folks in the city.

World War II Air Raid Shelters

In WWII, well shafts were enlarged and spiraling stairwells constructed under orders of Mussolini for public entry into air raid shelters 30 to 60 meters below the surface in the immense quarried caverns which were outfitted with lights and even showers. Some even had airtight doors to counter feared gas attacks.

Here is another example of stairs descending into the shelters below. Michael Quaranta, another senior speleologist, conducts daily tours of a huge air raid shelter beneath the old Spanish Quarter.
Scuffed, stained, well worn steps attest to the nightly descent by hundreds of fleeing Neapolitans as the air raid sirens began to wail.

Entire families huddled together as allied bombers rained bombs down upon Naples. Many, many families came back up to find their entire neighborhoods destroyed. They would grab what they could then returned to temporarily live in the caverns below.

Cavities were enlarged and interconnected with large tunnels like the one above, offering safety to thousands. This image is frozen in time with the old benches where refugees sat, now slowly crumbling as the decades pass after WWII .

Tunnels and other Mysteries

During the reign of the Bourbons, a huge tunnel was dug from the royal palace through the tall hill dividing the city. It was to a quick escape route to the bay on the other side of the city. It was large enough for horses and carriages to move through. Parts of the tunnel were used as an auto graveyard decades ago.

Having huge quarried caverns and tunnels beneath the city takes it toll today, with huge washouts and cave ins like this one not at all uncommon after torrential rains!

Today, entrances to huge cavities and tunnels are used for private storage, improvised parking and even auto repair shops.

We hope you have enjoyed this photo tour. We have many more photos of the incredible "Parallel City" beneath Naples which we will post from time to time .

For an excellent brief expanded overview of the variety of tunnels, cavities, passageways, history and such, visit our friend, Jeff Matthew's, great article in his 'Naples Encyclopedia' at: