The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

San Francisco's newly reopened hands-on science museum.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Frank Lloyd Wright died a year before construction on his largest public project even began.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

This Oakland fairytale kingdom, fiercely devoted to childlike whimsy, was an early inspiration for Disneyland.

Thousands of crosses and markers for soldiers who lost their lives in Iraq and Afghanistan blanket a California hillside.

A gap in the concrete has been transformed into a miniature playground for the mind.

This mountaintop beacon is only lit three times a year but shines like some kind of all-seeing eye.

Neoclassical Revival mansion and set of horror cult classic Phantasm.