This historic Amsterdam bar used to accept sailor's monkeys as payment.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

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

The world's only museum devoted to the wonders of fluorescence.

This enormous censer uses a pulley system installed over 400 years ago.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

Building owners can take out tiles for free at this repository for historic building materials.

Elaborate tile work in this railway station tells the story of Portugal.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

The stunning interior of this Gothic church is covered in ornate gold details.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

Two monstrous faces loom over a village in Czechia.

This former quarry is now a picturesque gorge that hides a sunken lake.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Walk through Czech history in Prague's largest graveyard.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

An existential riddle in the world's largest ancient castle.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

A series of playful yellow penguins share a serious message about the environment.

Macabre astrological automaton clock dating to the late 1400s.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

This spooky statue sits outside a famous Prague theater.