Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

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

This doorless 20th-century elevator doesn't stop or slow down.

Oddly enough, a pair of Wolfs funded the construction of this Little Red Riding Hood sculpture.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

Built in 1925, this glass-roofed shopping arcade is known for its modernist Italian architecture.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

An ornate century-old elevator still connects the two halves of Bad Schandau.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Inside this art museum resides one of Glasgow's most famous musical instruments.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

This frog-themed restaurant was frequented by Picasso, Saint-Exupéry, and more.

Now home to a drinking establishment, this building has a macabre history.

One of Edinburgh's oldest pubs hides a 19th-century skittles alley in the back.

One of the oldest masonic museums in Paris.

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

Architect Le Corbusier built his friend a cubist house to match his impressive collection of cubist art.

Got apples?

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

The narrowest street in Paris.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

Where the high court feasted, frolicked, and high courtesans put their royal lovers' diamonds to the test.

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."