Bourbon Tunnel, Underground archaeological site in Naples, Italy

The Bourbon Tunnel is an underground passage beneath Naples that extends roughly 700 meters and connects the Royal Palace area to Pizzofalcone hill. The network comprises several corridors and chambers that allow different routes through the complex.

The tunnel was commissioned in 1853 as a hidden escape route from the Royal Palace. During World War II, it served as an air raid shelter for the local population.

The site takes its name from the Bourbon dynasty that commissioned it. Volunteers who cleared the debris from 2007 onward found and put on display vintage cars and motorcycles seized by the courts and stored here after the war. A monument to Fascist leader Aurelio Padovani, inaugurated in 1934 and removed after 1945, was also recovered from the rubble in March 2010.

Exploring the tunnel requires a guide, as several different routes are offered. It is advisable to wear comfortable shoes, as some areas are tight and uneven.

The tunnel cut through the Carmignano aqueduct (1627–1629) without shutting it down: Alvino built two separate underground bridges to carry the water across the new passage. Ferdinand II was so taken with the solution that he opened the tunnel to the public for three days in May 1855.