When was your last underground archeological tour that entailed ziplining and sailing? 

It's well known today that Il Passetto of Rome was constructed as a secret passageway for Popes. But how do you escape in times of siege if you're the king?

In Naples lies an underground passageway that stretches from the Royal Palace all the way to... huh?
It ends in a parking lot.

But let's back up.

The Tunnel Borbonico was built by Bourbon King "The Bomb" Ferdinand II--son of "Big Nose" Ferdinand I, and equally unpopular among his subjects. The younger king ordered the tunnel constructed as an escape route in times of revolution, which pretty much meant Ferdinand's entire reign.

The passageway was planned to extend into Piazza Vittoria, which housed a military barracks. But it was never quite finished.

Today, the main entrance to Il Tunnel Borbonico can be accessed in Piazza Plebiscito, the large, central piazza of Naples in which the Royal Palace resides. A giant parking structure sits on top at the other end of the tunnel, but one can access the tunnel from within the parking lot.

Visiting Il Tunnel Borbonico is not your average walking tour through an underground chamber. While the "Standard Tour" is what one might expect--a walk through the tunnels, exploring the artifacts--the adventurous might want to try the "Adventure Tour." This one leads through still-flooded passageways and entails a raft ride beneath the city. And for those who would rather be in the sky beneath Naples (yes, you read that right), don your lighted helmet and follow the "Speleo Tour", where you get to zipline up a cistern.

For more information, visit the Tunnel Borbonico website.

This blog post explores a non-fictional theme or locale that is incorporated in the third Katrina Stone novel, as yet untitled, by Kristen Elise. Buy The Vesuvius Isotope, the first Katrina Stone novel, in printor ebook.

From the ancient ruins beneath Mount Vesuvius, a two-thousand-year-old document has emerged. It is the only text ever attributed to the ambitious, inquisitive, and cryptic last pharaoh of Egypt...

When her Nobel laureate husband is murdered, biologist Katrina Stone can no longer ignore the secrecy that has increasingly pervaded his recent behavior. Her search for answers leads to a two-thousand-year-old medical mystery and the life of one of history’s most enigmatic women. Following the trail forged by her late husband, Katrina must separate truth from legend as she chases medicine from ancient Italy and Egypt to a clandestine modern-day war. Her quest will reveal a legacy of greed and murder and resurrect an ancient plague into the twenty-first century.



Kristen Elise, Ph.D. is a drug discovery biologist and the author of The Vesuvius Isotope. She lives in San Diego, California, with her husband, stepson, and three canine children.