Colorful Native American paintings are hidden within this small cavern.

Hidden in the Santa Ynez Mountains off Highway 154, this tiny restaurant once served as a stagecoach stop.

The ruins of the castle that chemicals built.

The mysterious, untimely death of a Canned Heat band member still haunts this unfinished home.

Home to one of the world’s largest collections of model yachts.

San Francisco's first World's Fair, dedicated to the wonders of California.

Guns that have been defending San Francisco since 1904.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

This grinning pup statue is all that's left of what was once a ubiquitous Bay Area diner chain.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

A hidden subterranean installation offers a view of the sky.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

The remains of a ruined mansion memorialize the 1906 earthquake.

Tiki luxury on Nob Hill.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

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

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

Faceless white figures loom over the city from the rooftop.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

What appears to be a wizard's lair in Milwaukee actually houses a massive water pipe.

A wonderfully curated used bookstore in an airport.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.