Napoli Sotterranea, Naples

Napoli Sotterranea opens onto a vast human-made world beneath the city: tunnels, galleries, waterworks and excavated chambers shaped by changing needs across Naples’ history. This underground network began taking form centuries before the common era and remained in use until a few years after World War II; parts of it can still be visited today. Its scale is striking: about 900,000 square metres of artificial cavities are known beneath the urban area, and only two of them are natural.

Their uses ranged from cutting building stone and carrying water to burial, military defence and shelter during wartime bombing. In the narrow aqueduct passages, the channels often branch in many directions to supply homes and fountains above. Traces of waterproof plaster still cling to some walls, offering a direct glimpse of ancient engineering.

Later, these spaces became air-raid shelters, and some were even used to store confiscated vehicles. What you encounter here is not a single underground room but a layered city beneath the visible one, still being explored as hidden chambers emerge during building work and excavation.