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

An Aladdin's cave of old Silicon Valley tech.

Hidden among the multi-million dollar mansions in the Santa Cruz hills is a sanctuary for troubled birds.

San Francisco Bay's ghost town.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

A Roman-inspired temple once controlled half of San Francisco's waters.

The Internet Age began with a transmission from this biker bar.

This odd California folly seems like it was almost designed to accumulate urban legends.

Successful artist residence program has filled this ranch with dozens of sculptures over the years.

This cabin once belonged to one of California's original settlers.

Nursery with extensive collection of flesh-eating plants operated by the author of "The Savage Garden."

This small monument to the great inventor contains a time capsule and a Wi-Fi hotspot.

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

A hidden world of exotic succulents and cacti.

Four miles of pipelines form the model of still-functioning retro-tech efficiency.

The haunting ruins of Jack London's dream house.

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

An enchanting tunnel of cypress trees leads to an old morse code station still used today.

The rusting remains of the largest assembled WWII fleet on the West Coast.

A trail weaves through the verses of a poem illustrated by stone sculptures inspired by Native American pictographs.

Built by the inventor of the radio, this abandoned hotel has housed early radio employees, military men, and a dangerous cult.

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

The final resting place of a woman who never gave up on love.

Nuclear waste dump site now an environmental sanctuary.