Naples from below: 2,400 years of tunnels

The Greek city of Neapolis cut its building stone from below. Napoli Sotterranea dates the cavities under Piazza San Gaetano to the 4th century BC, and says they supplied the city's water for about 23 centuries. The Hydria project, which studies ancient water systems, credits the Greek city with the Bolla aqueduct, about 10 km long, and the Romans with the far larger Serino aqueduct, about 100 km, built around 30 to 20 BC.

The pattern repeated for centuries: stone came up to build the city, and the hollows below were used to store water from the aqueduct channels. The city also built over its own past. The Greco-Roman theater of Neapolis vanished into the houses on Via Anticaglia: from the 15th century, homes were built into its curved walls. Napoli Sotterranea's ticket includes a visit through one of them, where a guide moves a bed and opens a trapdoor. The operator says the rooms below were Nero's dressing rooms; treat that as a story, not history.

Outside the Greek walls, the same stone took the dead. The Catacombs of San Gennaro, cut into the tuff of the Capodimonte hill, began as a family burial ground in the 2nd century AD and grew after the burial of the bishop Agrippinus in the 4th. Their galleries are wider and higher than the famous catacombs of Rome. The €13 ticket also covers San Gaudioso, under the Basilica of Santa Maria della Sanità, within 12 months.

Further up the valley, the old quarries of the Fontanelle became an ossuary. The Comune's history links it to the plague of 1656 and to the cholera dead of 1837, and in 1872 a parish priest and local women put the bones in the order you see now. It reopened on April 19, 2026, after years shut, and every visit must be booked. Our Rione Sanità walk links both.

In 1629 Cesare Carmignano built a new aqueduct for the growing city. Keeping the water system working was the job of the pozzari, the aqueduct's maintenance men, who moved through narrow channels under the city. You can walk some of those channels on the Galleria Borbonica's Adventure route.

The system ended with a disaster. A cholera epidemic hit Naples in 1884, and on January 15, 1885 a national law funded the Risanamento, the rebuilding of the city's worst districts and its sewers. A modern pressure aqueduct, begun in 1881, replaced the old supply, and the cisterns lost their purpose.

On February 19, 1853, King Ferdinand II signed a decree for a tunnel under Monte Echia, linking the Royal Palace with the barracks near the sea: a route for troops, and an escape for the royal family after the uprisings of 1848. The architect Errico Alvino's workers dug it by hand, by torchlight, from April 1853 to May 1855. They kept breaking into the older cisterns and had to bridge them. The tunnel ended 431 m long, at Piazza Carolina behind Piazza del Plebiscito, and never reached the Palazzo Reale.

In the Second World War the empty cisterns became air-raid shelters. The Galleria Borbonica says 5,000 to 10,000 people sheltered in its tunnel between 1939 and 1945; Napoli Sotterranea says about 40,000 people lived in the city's underground during the raids. Those are the operators' own figures, and we found no independent count. Napoli Sotterranea's war museum dates the raid that all but destroyed Santa Chiara to August 4, 1943; the rebuilt basilica tells that story above ground.

After the war, the underground became a dump. Napoli Sotterranea says rubble from the bombed city was thrown back down the old wells, and the Galleria Borbonica served as a police car pound until 1970. Excavation from 2007 uncovered cars, motorbikes and statues under 8 m of debris; the Adventure route is the one that promises the room of vintage vehicles.

The digging has not stopped. Toledo station on metro Line 1, opened in 2012, goes down about 44 m, for the price of a €1.30 ticket.

If you do one, do Napoli Sotterranea: it is central, open every day and covers the longest span of history. It involves 136 steps down to about 40 m and back, with no lift. Our Sotterranea or Borbonica comparison goes into detail. A MANN ticket gives 25% off at the Galleria Borbonica and the catacombs.

Naples: Naples Underground Entry Ticket and Guided Tour

€18, the same as the full price on napolisotterranea.org. Guided only; 121 steps and not wheelchair accessible. Meets at Piazza San Gaetano 62, while the association's site gives its entrance as number 69; neither page says the two sellers are the same.

1.5 to 2 hours

4.4★★★★★★★★★★(25,854 reviews)

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Rating as shown on GetYourGuide

Naples: Catacombs of San Gennaro Entry Ticket & Guided Tour

Sold by the catacombs' own operator, Catacombe di Napoli. Timed and non-refundable: be at the ticket office, Via Capodimonte 13, 15 minutes early. The San Gaudioso part is valid for 12 months.

45 minutes

4.6★★★★★★★★★★(8,815 reviews)

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Galleria Borbonica Entrance Ticket in Standard Route

Same €15 as the Galleria's own adult price. Entries at 10 am, noon, 3 pm and 5 pm from Vico del Grottone 4. The listing's child prices differ from the Galleria's own page, so check before booking children.

1 hour

4.9★★★★★★★★★★(2,849 reviews)

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Rating as shown on Viator

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