This bronze statue of Martin Luther King was placed in the park without permission.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

Sail in for a ’dam good slice.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.

This unattributed sculpture in Amsterdam is hiding in plain sight.

A beautifully eclectic mix of architectural styles.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The history and future of cannabis.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

The narrowest street in Paris.

With a history of slaughter, feast, and famine, remnants of the pork industry decorate this area--even its church.

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

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

The bronzed skull of a beheaded traitor was affixed to the city gate in the 17th century.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

Explore 400,000 years of humans' "battle against darkness" in this offbeat but thorough lamp museum.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The footprint of a frustrated devil in Munich's Cathedral.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.