An unusual round church in London with a Templar past.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

British troops and Prohibition couldn’t stop this spot from becoming one of the United States' oldest continuously-run taverns.

A grave surprise in the downtown area of New England's second-largest city.

The Burnside Fountain and its questionable interpretation.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

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

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

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

This building features dozens of faces along its facade, although one is a bit chilling.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

Time has been frozen at this station since the bombing in 1980—or so it was believed.

Built as a defensive structure, this medieval walkway road offers a unique view of the village of Brisighella.

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

Legend says this mysterious stone head belongs to a woman who was petrified by an alchemist.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

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

Renaissance villa and gardens complete with a tormented colossus.

A 16th-century horror show built in a lovely Italian garden.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.