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

Canyon walls shrouded in ferns.

Abandoned bridge hidden deep in the San Gabriel Mountains.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

An eclectic trailer park retreat in the middle of the California desert.

A Swedenborgian glass church surrounded by redwoods sits perched atop a massive landslide area.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Historic marionette theater features thousands of handmade puppets and free cups of ice cream.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

Olfactory delights in San Francisco's Botanical Gardens.

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

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

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

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

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

Panorama exhibition hall in old silent theater with a beautiful backyard garden.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A winding path built in secret on the edge of the continent.

Towering basalt columns, a creation of fire and ice.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.