A common entry point to the Griffith Observatory trail holds its own wonders.

Travelers exchange letters with woodland creatures at this mini post office.

The remains of a ruined mansion memorialize the 1906 earthquake.

An unfortunate geological resemblance to Satan has labeled this Pasadena gorge as a passage to the underworld.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

The last of its kind in the country.

An inconspicuous footbridge beloved by San Diego locals.

The remains of the first punk club in L.A.

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

Explore 10 acres of environmental sculptures.

"Looks so real, it's scary!"

Stripes of flowers bloom each spring in a 50 acre rainbow of color.

A meditative space out of a fantasy story.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

One man's vast collection of artifacts and ephemera from matchbooks and postcards to vintage neon signs and cars.

Carved by a waterfall in a hard-to-reach rock formation, this heart-shaped rock has inspired romantics for decades.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

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

Each year these high desert hills are absolutely covered with poppy flowers in a surreal show of nature.

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

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.