Above ground Naples is already beautiful, but below the city is a whole other world of caves, catacombs, galleries, storerooms, tunnels and old watercourses, carved in tuff. Underground Naples (Napoli Sotterranea) is one of the unique sights in Naples. The Greeks and Romans already used the tuff to build their city walls and temples. There were also underground watercourses. The houses above it had access to that water via a deep well. The result of thousands of years of digging into the ground of Naples is a unique and vast underground system. During the Second World War, the underground tunnels served as air-raid shelters.
In the days when Christianity was forbidden in Roman times, Christians sought a safe place to profess their faith and bury their dead. That too was done underground. Especially under the eastern part of Naples you will find those Christian shelter churches.
There are also caves dedicated to San Gennaro, the patron saint of Naples. One of these caves is near the church of Madre di Buonconsiglio. You will see one of the oldest portraits of Saint Gennaro, probably from the 5th century.
The caves also served as a cemetery and that can be seen in the Fontanelle Cave: there are thousands of skulls and bones, remains of people who died of the plague in the 16th century. At the height of the epidemic, 1500 people a day died and were buried in the caves. Later the cave also served as a cemetery for the poor of the city. Around these skulls a kind of cult grew: people who 'adopted' a skull and regularly visited 'their dead'. That cult was banned in 1969. The cave was closed and can now only be visited as part of the tour.
At the basilica of San Lorenzo Maggiore on Via dei Tribunali you can see something completely different underground: the remains of the Greek city of Neapolis.
Website: Naples Underground Vico S. Anna di Palazzo
Address: Vico S. Anna di Palazzo 52
Website: Naples Underground Piazza San Gaetano
Address: Piazza San Gaetano 68
Consult the websites for up-to-date price information and departure times.