Nuclear waste dump site now an environmental sanctuary.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

The sole surviving relic of the San Francisco neighborhood cobbled together from old horsecars and streetcars.

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

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A 300-ship graveyard, with a few still visible at low tide.

A modest reminder of treacherous waters at the Golden Gate.

9,000 square feet of vintage and modern mechanical toys, dioramas & sideshow curiosities.

A sparse, solitary sequoia still stands as a living tribute to the famous conservationist who planted it—but it's dying.

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

Haunting and beautiful trees, doomed to die.

Where a staggering 747 ships were constructed during World War II.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

This municipal playground was co-created by the father of one of the most playful characters ever.

Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

A tree grown from astronaut seeds which were exposed to cosmic rays.

The oldest continuously operating church in California.

Hopeless romantics will swoon over the sweet story behind this bright and colorful home.

The oldest lighthouse on America's west coast no longer needs keepers, yet they maintain the site anyhow.

Two rocks in a perpetual kiss and one of "the most romantic spot in America."

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

This railroad magnate's 19th century tower is more than a little bit out of place in the Nevada desert.

This central Nevada cave is the spiritual home of ancient and enigmatic pictographs.

This cave was hidden for thousands of years, storing the worldly goods of ancient Native Americans.