Concrete strongholds stand guard over the Golden Gate.

An abandoned, unfinished mansion on grounds strewn with lava rocks.

The lighthouse central to the 1980s horror classic "The Fog" is, in fact, located in one of the foggiest areas of the Pacific Coast.

A tribute to one man's legacy of improving the accordion's reputation.

The southernmost outpost of the Russian Empire in colonial America.

Hand-powered race of alternative forms of transportation.

A poignant memorial to a young boy whose death spurred a dramatic increase in organ donations in Italy—dubbed the "Nicholas Effect."

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

George Lucas donated this park to honor the birthplace of his two biggest movie franchises.

The unedited photograph called "Bliss" has graced the screens of over a billion computers.

A crumbling Beaux Arts monument to the Bay Area's age of rail.

A temple devoted to inner esoteric mysteries located in a California commercial strip.

An abandoned convention space that has been left to the homeless and the radical.

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

This restaurant offers the original California cuisine.

An abandoned car and strange wooden debris are among the scattered remains of the old sand and gravel quarry.