A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

World's first "penitentiary," meant to be humane, drove men insane.

Rippling sand dunes frozen in the Arizona rock.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

An invitation-only museum of items natural and bizarre, arcane and exotic.

Furniture tries to escape an abandoned building in San Francisco.

Sitting atop San Francisco's tallest hill, a cross honors the victims of the Armenian genocide.

A bronze tribute to a legendary Californian, the self-proclaimed "Emperor of the United States."

The first fresco Diego Rivera painted in the United States can be found in the former San Francisco Stock Exchange.

A quiet nook at the top of a little-known hilltop park named after California's first poet laureate.

This Japanese treats shop may have been the first business to mass-produce fortune cookies in the United States.

Approximately 250,000 people left homeless by the great earthquake and fires found shelter in Golden Gate Park.

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

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

This surreptitious shop is only open five hours per week.

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

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

An enormous artwork that colorfully celebrates over 150 years of US military achievements.

A monumental cross hides in the trees in Golden Gate Park.

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

From silent movie theater to rock &roll palace and beyond.

A California city claims to be the home of a fast-food classic.

"The Star Factory" cranked out Hollywood stars like nobody's business.

A rare surviving example of a pre-WWII Japanese garden, restored after years of neglect.