The Bourbon Tunnel, or Galleria Borbonica, is a subterranean passage cut through the soft tufa beneath Naples. Commissioned in 1853 by Ferdinand II of the Kingdom of the Two Sicilies and designed by architect Enrico Alvino, it was intended as a military route connecting the Royal Palace with the barracks and seafront. The passage was never completed, but it intersected older aqueduct channels and cisterns that had supplied the city with water.
A guided tour reveals how the tunnel acquired new roles long after the Bourbon plans were abandoned. During the Second World War, Neapolitans sheltered here from air raids, leaving traces of daily life underground. Later, the spaces became a municipal vehicle pound; vintage cars and motorbikes remain among the rock-cut chambers. These layers make the Bourbon Tunnel one of the most intriguing ways to explore Naples beyond its streets and palaces.
Several guided routes are offered, ranging from relatively straightforward walks to more adventurous trips through the cisterns. Book ahead, especially at weekends, and check the meeting point for your chosen tour. Wear sturdy shoes and bring a light layer: the tunnel is cool, and the ground can be uneven or damp. Visitors with limited mobility or concerns about confined spaces should check route details before booking.