This state park was once an important Native American cermonial center.

One of the world’s largest and deepest freshwater springs, where mastodons once roamed.

A world-class observatory in the California desert.

A modest reminder of treacherous waters at the Golden Gate.

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.

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

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

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

One time home to turn of the century explosives, now hidden under the Bay Bridge.

Condemned US Navy seaplane control tower turned officers’ club sits atop Yerba Buena Island.

The liveliest ghost town in the state.

This unique graffiti art from the 1940s has become a staple of this local landscape in the remote California desert.

One of the most unusual geological features, recognizable from a dozen hit movies.

This sun-scorched lakebed contains samples of half the natural elements known to humankind.

Salt is slowly eating away this abandoned saltworks town in the desert.

Colorful Native American paintings are hidden within this small cavern.

An expansive and intricately restored mansion remains from over a century ago--and so do its ghosts.

Where the writer penned his famous story about a jumping frog.

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

This turn of the century masterpiece has a mysterious goaty interloper.

This statue honors the author's groundbreaking family story.

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.