This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

This classic restaurant features a gorgeous mirror-clad room.

A slice of central Asia in the middle of Berlin.

An eerie, derelict amusement park in Berlin.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

Visible below the waves are memorials to the city's Gold Rush dead.

Art from the latest counter-culture; kids who dye their hair blue and believe the future will be a post-apocalyptic water world.

A huge musical instrument played by the ocean.

The tea room that pushed the boundaries of adorable straight into...we can't find the words.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

This subtle Berkeley paving stone actually marks off a lawless tube of air that extends into space.

A playground built by the kids that is a child's wonderland, and a helicopter parent's nightmare.

A creepy steel gremlin has protected the Bay Bridge since 1989.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.