To find the "unicorns of the deep" you've got to go downstairs.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

These pretty kitties killed and ate as many as 135 railway workers.

The world’s largest street art museum.

This spooky statue sits outside a famous Prague theater.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

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

Macabre astrological automaton clock dating to the late 1400s.

A Jenga-style cylindrical tower of books that appears to go on forever.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

A man throwing a giant severed hand towers over Antwerp’s main square.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

A diverse, expansive nature preserve in northeastern Kansas.

Self-built house and sculpture park where the creator can still be seen in a glass coffin.

Lone survivor from Custer's Last Stand forever preserved.

A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

An ancient Egyptian temple sits within a modern European museum.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

Collective made up of artists, musicians, and activists.

This feline raises a friendly paw at drivers barreling toward the freeway.

The world’s largest Masonic temple was saved by the White Stripes.

A Beaux-Arts triumph rises from decades of decay to become the heart of a new innovation district.

Detroit’s downtown castle is one of the oldest structures in the city.