Underground Naples is a city hidden beneath the city, a labyrinth of cisterns, tunnels, and ancient aqueducts carved into the tuff rock about 40 meters deep, revealing over two thousand years of history in just a few steps. In this silent underbelly, traces of the Greeks, Romans, and Bourbons can be found, and even signs of the Second World War, with tunnels used as air raid shelters and graffiti left by evacuees. It is a true "parallel city," hundreds of kilometers long, of tunnels and cavities created by the extraction of tuff rock to build the Naples above ground.

The same spaces were reused over the centuries as a Greco-Roman aqueduct, as a system of cisterns and then as air raid shelters during the bombings of the twentieth century. The route also includes a small “war museum” and, on some itineraries, access to the Greco-Roman theatre hidden beneath a typical Neapolitan bass, reachable through a trapdoor hidden under a bed. Visiting Underground Naples means seeing, in about an hour and a half, the real stratification of the city: from the Greek cuts in the tuff to the Roman tunnels, up to the Bourbon galleries and the traces of daily life during the war. It's an experience that no other attraction offers with the same intensity, because it gives a physical perception of how Naples is built – materially and symbolically – on its bowels, transforming a simple guided tour into a journey through time that remains as memorable as a view of the Gulf.