Under the hill of Pizzofalcone, between piazza del Plebiscito and Chiaia, runs a tunnel dug by hand in the mid nineteenth century for a king who feared revolution. Ferdinand II of Bourbon wanted an escape route from the royal palace to the sea; what he got was a tunnel never finished, wide enough for carriages, which eighty years later saved thousands of Neapolitans from the bombs.
Today the Bourbon Tunnel is visited with a guide, among the sixteenth century cisterns of an aqueduct, the messages left on the walls by people who lived here during the war and dozens of vintage cars and motorcycles. It is not to be confused with Naples Underground at piazza San Gaetano, the Greco-Roman aqueduct beneath the old centre, or with the complex of San Lorenzo Maggiore: Naples has at least three underground sites you can visit.
Here the calendar works the other way round: the Bourbon Tunnel doesn’t close one day a week, it opens three days out of seven. Tours run Friday, Saturday, Sunday and public holidays, at fixed times and with booking required, so if your weekend in Naples starts on Monday, this visit doesn’t exist for you.
And how did the vintage cars everyone photographs end up down there?
Why a king digs a tunnel under his own palace
What drives a sovereign to build an escape route under his own house? A fear with a date attached. In 1848 the Kingdom of the Two Sicilies is shaken by revolutionary uprisings, and Ferdinand II of Bourbon comes out of it convinced the royal palace needs an exit that doesn’t pass through the street.
On 19 February 1853 the king signs the decree and hands the project to Errico Alvino, at the time special commissioner for via Chiaia and San Ferdinando. On paper the work has two purposes, both military: a passage for troops quartered in the Chiaia barracks, so they could reach the palace within minutes, and an escape route to the sea for the royal family.
Alvino didn’t design a narrow shaft. He drew up an underground viaduct with a trapezoidal cross-section, twelve metres wide and twelve high, with two lanes and pavements on either side: carriages were meant to pass through it. Walking it, you notice the scale before anything else, and that scale is the reason the work was never finished.
The four hundred and thirty-one metres that never reached the palace
Work to open the route began in April 1853 and stopped in May 1855, after roughly three years of digging done by hand. Then it halted: the money ran out, and Italian unification took the project’s patron along with the kingdom.
The result is that the four hundred and thirty-one metres planned to reach the royal palace were never completed, and the tunnel remained an infrastructure cut short. This isn’t an ancient ruin: it’s a nineteenth century building site closed in a hurry, and you can see it in the pickaxe marks on the walls, which in places stop abruptly where the man swinging them gave up.
Keep this date in mind: everything the tunnel did afterwards it did by chance. A work built to carry a king to safety would serve, eighty years later, to carry to safety the city he once ruled.
The Bolla aqueduct, and the bridges built to keep it running
The technical detail that makes this visit different from an ordinary walk through a tunnel is how the passage meets water. While digging, Alvino’s workers cut into the sixteenth century cisterns of the Bolla aqueduct, which in the mid nineteenth century was still in service and carried water to the city.
How do you cross a working reservoir without draining it? The Bourbon answer is the best thing you’ll see down here: engineers built three bridges and retaining walls to span the cisterns while leaving them to their job. The tunnel passes above the water, the water keeps flowing below, and neither structure had to give way to the other.
It’s a piece of civil engineering nobody was meant to see, sealed as it was inside a secret military work. Look at where the bridges meet the rock: the nineteenth century masonry and the sixteenth century cut of the tuff touch each other, and the difference between the two is visible to the naked eye.
Five thousand people underground, and the walls that recorded them
Between 1939 and 1945 the tunnel and the nearby cisterns became the city’s largest air raid shelter. Between five and ten thousand Neapolitans settled here, many of whom no longer had a home: Naples endured roughly two hundred bombing raids, and those left without a roof came down here and stayed.
To take in that crowd, new entrances were opened, electricity was brought in and services were built. But the detail that strikes hardest isn’t a structure: it’s the handwritten messages on the walls, left by people who spent months underground. Names, dates, phrases, children’s drawings.
None of it has been staged or rebuilt. It’s the reason this visit, on paper industrial archaeology, in practice reads as a piece of twentieth century history written on the walls.
The cars are not a car museum
Inside the tunnel there are dozens of vintage cars and motorcycles, and it’s the part everyone photographs and almost everyone gets wrong. It isn’t a collection: it’s what remains of a judicial storage depot.
From 1945 to 1970 the Naples police used the tunnel to store material recovered from collapsed buildings, evictions and seizures in the postwar years. The vehicles arrived one at a time and stayed where they were put. That they now look like a museum is an effect of time, not a plan.
The tunnel also holds statues from the Fascist era, which arrived the same way. Looking at them knowing they ended up here because someone carted them away from a square, not because someone chose to display them, changes what you’re seeing completely.
Which of the four routes to choose
The operator runs four different tours, and the choice isn’t obvious, because the two main ones cost the same.
The Standard Route takes about an hour, enters from vico del Grottone or the Morelli car park, and crosses the tunnel, the cisterns and the vehicle area. It’s the right one if you’re short on time or travelling with small children.
The Route of Memories takes an hour and a quarter and covers more ground: Palazzo Serra di Cassano, a small war museum, the tuff quarries, the aqueduct with its cistern, and the crossing of the tunnel. Watch out: it isn’t accessible to everyone, because it involves stairs. At the same price, it’s the richer visit, and it’s the one I recommend if you can walk without difficulty.
That leaves the Adventure Route and the Speleo Light, tours that require equipment and a different level of fitness. Prices and days for these two aren’t published on the pages I checked: ask the operator directly, and the contact details are below.
Practical information
Data checked on 10 September 2026 on the tunnel operator’s website. Prices and hours change: check again before you travel.
Tickets. Full price is 15 euros and includes the guided tour, the only way down. The reduced price is 10 euros and applies to ages 6 to 18, over 70s and law enforcement staff. People with disabilities pay 7 euros and children up to 5 get in free. The price is the same for the Standard Route and the Route of Memories.
Watch out for a price that circulates and isn’t the operator’s. Some resale platforms list the standard route at 10 euros: that’s a different package, put together by a middleman, not the entrance fee. The number to trust is the one published by whoever runs the tunnel.
Hours. Tours run Friday, Saturday, Sunday and public holidays. The Standard Route departs at 10:00, 12:00, 15:00 and 17:00; the Route of Memories at 11:00 and 16:00. On other days you can go down only by booking. Booking is required in every case.
Getting there. There are three entrances. Vico del Grottone 4 is a few steps from piazza del Plebiscito and is reached down a staircase built in the eighteenth century. Via Domenico Morelli 61 is the monumental entrance, inside the Morelli car park. Via Monte di Dio 14 is through Palazzo Serra di Cassano, and serves the Route of Memories. By metro line 1, get off at Municipio or Toledo; by the Centrale funicular, at Augusteo.
Contacts. Bookings are taken on 366 2484151 and 081 7645808, or by writing to mail@galleriaborbonica.com. Check the calendar on the website before you go: the operator publishes openings day by day, and dates do occasionally get cancelled.
How much time it takes. An hour for the Standard Route, an hour and a quarter for the Route of Memories, guide included. Arrive a quarter of an hour before your slot departs.
What to wear. The temperature underground is constant and lower than at street level, so bring something with sleeves even in summer. Closed shoes are needed: the floor is uneven in places and damp in others.
The rest of Naples
From the tunnel you’re two steps from the Royal Palace with its historical apartment, the palace the tunnel was meant to reach and never did: doing both in the same half day closes the loop. Watch the days: the palace closes on Wednesdays, the tunnel opens Friday to Sunday, so the weekend works for both. Five minutes further on is Castel Nuovo, which closes instead on Sundays.
To stay underground, the other visit to make is Naples Underground at piazza San Gaetano: the same depths, two thousand years apart. Toward the hill, Rione Sanità with its catacombs is the third chapter of the same story.
Heading back up toward the centre you’ll find the Sansevero Chapel, the majolica cloister of Santa Chiara and the lower decumanus with the Donatello at Sant’Angelo a Nilo. If you need the full two day sequence, with closing days, it’s in what to see in Naples in 2 days.
Photo credits: the four photographs are by the Associazione Culturale Borbonica Sotterranea (CC BY-SA 4.0), via Wikimedia Commons.
