Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

The location of the last witch trials of Italy, known as "The Salem of Europe."

A Nesting Doll of Churches.

This 16th-century monastery has been turned into a surrealist architecture compound.

The final resting place of the poets Shelley and Keats.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

A beloved local artist has been honored with this statue of a man emerging from a toilet.

Tiki luxury on Nob Hill.

A castle that was built stone by stone by an eccentric journalist.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

Drink wine handed out through a window as part of an age-old tradition.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Overlooked amid the tourist bustle of Florence, this museum is dedicated to the craft of stone inlay.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

The middle finger of modernity.

The Bourbon royal family had this unique octagonal hunting "cottage" built on a tiny islet in Lake Fusaro.

A fairy tale castle in modern Rome.

Venice's "Island of the Mad."

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

Europe’s oldest natural human mummy.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.