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

A meditative space out of a fantasy story.

Canyon walls shrouded in ferns.

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

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

Quite simply the largest tree in the world (by volume).

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

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

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

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

Crypt mausoleum in cathedral's basement contains relics of third century Roman martyr, Saint Vibiana.

Towering basalt columns, a creation of fire and ice.

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

Giant Redwood-themed cafeteria operates under the golden rule, "Dine Free Unless Delighted."

The rocks in this arid basin leave trails of movement behind them.

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

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

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.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

World's largest collection of serial killer artwork and other macabre exhibits.

A psychedelic labyrinth on the San Francisco bay.

An artsy hidden staircase leads to breathtaking views of San Francisco.