The plague quarantine island home to the alleged "Vampire of Venice."

The profile of one ill-fated deacon was emblazoned forever on this church window during the Halifax explosion.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

The topiary maze at the Habsburg hunting lodge.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

2300-year-old Roman road connecting the empire.

This well-preserved Cistercian Abbey in a romantic pastoral setting has inspired artists like the poet Wordsworth.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A close look reveals that the Scottish monument is just slightly off-kilter.

A treasure trove of astronomical, mathematical, and scientific instruments at Cambridge University.

The Cambridge pub where Francis Crick announced that he and James Watson had discovered the DNA double-helix.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Repository for more than 22 million pickled specimens.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

France's most famous cemetery, with some of its most curious tombs.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

An exercise in patience and imagination, where Mother Earth turned common stuff into precious hidden treasures.