
Layered with history, as mesmerising as Naples is above ground the ancient city is also home to a mysterious warren of tunnels carved into 16th century aqueducts, 100 feet below ground.

And what makes these tunnels all the more intriguing is that they were built by a king, became littered with discarded motorbikes, rusting vintage cars and water tanks in the 1950s and were then long forgotten.

Accessed via an 18th century staircase not far from the Piazza del Plebiscite in central Naples, in the early 2000s locals re-discovered and transformed the passageways into a quirky tourist attraction - Galleria Borbonica.

Accessed via an 18th century staircase not far from the Piazza del Plebiscite in central Naples is a mysterious warren of tunnels. Inside visitors can find the rusting relics of vintage cars, above

Impounded retro motorbikes languish 100 feet below ground in the 16th century aqueducts

The intriguing Bourbon tunnel was originally designed for King Ferdinand II of Bourbon as an escape route connecting the royal palace and the army barracks in 1853

The secretive passageways were designed in response to the spate of revolts the monarch faced during his volatile reign

Brave tourists can explore the 1,740ft-long tunnels snaking through the city on a tour of the eerie space, which has had several uses over the years.

The Bourbon tunnel was originally designed for King Ferdinand II of Bourbon as an escape route connecting the royal palace and the army barracks in 1853.

The secretive passageways were designed in response to the spate of revolts the monarch faced during his volatile reign.

The king died before the tunnels were completed but they served a number of purposes until the 1960s when they fell into disuse and were forgotten

The passageways and aqueducts offered refuge as a military hospital and bomb shelter during World War II

Snaking 1,740 feet along the city, the structure was built into the volcanic rocks of the Bolla and Carmignano aqueducts

The tunnels became a warehouse for impounded vehicles from the 1940s until the 1960s

Visitors crawling through the tunnels nowadays will be sure to encounter the dusty relics of vintage cars and retro motorcycles abandoned underground

Eager to make use of the city’s ancient aqueducts, a plan was devised to build the structure in the cisterns of the Bolla and Carmignano aqueducts.

The king, however, died before the tunnels were completed, according to Amusing Planet.

With the regal route no longer necessary, the tunnels served many purposes over the years, with this ample space providing storage and protection to the few citizens privy to its existence.

The passageways and aqueducts offered refuge as a military hospital and bomb shelter during World War II and then became a warehouse for impounded vehicles from the 1940s until the 1960s.

Rows of discarded vespas line the passageways - a treasure trove of historic wonders

In the early 2000s locals re-discovered and transformed the passageways into a quirky tourist attraction - Galleria Borbonica

Galleria Borbonica devised three different types of tours to satiate the curiosity of locals and tourists alike

On a standard tour, you can walk inside the tunnel, see the bomb shelters and water tanks

This incredible image shows an exquisite picture on one of the rusting vehicles

The speleo tour allows visitors to enjoy a hands-on gritty experience crawling through the tunnels wearing helmets with torches

Layered with history, as mesmerising as Naples is above ground the ancient city is also home to a mysterious warren of tunnels. This image shows the grand scale of the underground city

Tourists can take a raft ride through one of the flooded tunnels, with guides lighting the way with lanterns

Visitors crawling through the tunnels nowadays will be sure to encounter the dusty relics of vintage cars and retro motorcycles that have been abandoned underground.

After rediscovering these incredible passageways, Galleria Borbonica devised three different types of tours to sate the curiosity of locals and tourists alike.

On a standard tour, you can walk inside the tunnel, see the bomb shelters and water tanks. The high-octane adventure tour includes a raft ride in a subway tunnel, which has become flooded with water.