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

This surprising gem is a world-class archeological museum hidden at the University of Chicago.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

The world's only known button museum.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

A hollow cement depiction of time's inexorable effect on the human body.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

A floating cat sanctuary on an Amsterdam canal.

Furniture tries to escape an abandoned building in San Francisco.

A century and a half of research in the sciences and natural history, still going strong.

San Francisco’s century-old Christmas Tree.

At the base of the Golden Gate Bridge, a small sign basically begs for a high-five.

Depicting scenes of everyday life - and specific individuals - in Great Depression era San Francisco.

27-room home built with the fortune of a sugar magnate.

Art in the form of a winding, man made crack in stone.

Created in 1972, the famous sculptor's intricately detailed monument to San Francisco is overflowing with city landmarks.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

This grinning pup statue is all that's left of what was once a ubiquitous Bay Area diner chain.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

Faceless white figures loom over the city from the rooftop.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

A garden oasis filled with flowers mentioned in the works of William Shakespeare.