A mountain range on an active U.S. Navy base hides thousands of mysterious prehistoric rock carvings.

This cave was hidden for thousands of years, storing the worldly goods of ancient Native Americans.

The ghostly remains of an accidental sea.

The tragedy of the Japanese internment camps is remembered here by a stark "Soul Consoling Tower."

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

Concrete strongholds stand guard over the Golden Gate.

Ten 25-foot-tall, beehive-shaped kilns, abandoned in Death Valley.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

A lawless town deep in Death Valley was famous for its riches and death rate turned YouTube famous.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Offering commanding views of the California coastline, this restaurant was a hub for the artists and bohemians of Big Sur.

A charming desert roadside bakery that produces 10 times more bread daily than it has residents in its town.

Roman ruins top white travertine terraces formed by ancient hot springs.