Underground Naples

At the end of the street stands the San Paolo Maggiore Basilica, itself built atop a Roman temple dedicated to the twin gods Castor and Pollux. The interior is stunning and definitely worth a visit. Nearby, you’ll also find the entrance to Naples’ fascinating underground tunnels – an extensive network stretching 80 kilometers with nearly 5,000 chambers dating from various eras and serving countless purposes. These tunnels were first carved out around the 5th century BC by the Greeks, who used them as tuff quarries, – the porous volcanic rock they used to fortify Neapolis. The Romans later took over, converting parts into water cisterns. This ended abruptly in 1884 when a cholera outbreak made the water unsafe, and the underground spaces became dumping grounds. During World War II, however, the city renovated and disinfected the tunnels, and even brought electricity to turn them into bomb shelters that protected over 200,000 people during and after the war. It's a one-of-a-kind, fascinating tour, though it’s ticketed — and exploring Naples Underground is one of the best ways to see the city from a whole new angle.