A stealthy Apache hideaway that became the haunting site of a mass grave.

Despite being a perfectly pleasant place to be, Loyalton can't seem to attract any visitors.

Rippling sand dunes frozen in the Arizona rock.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

The haunting ruins of Jack London's dream house.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

The largest drain hole in the world.

Law-protected wreckage serves as a peculiar memorial for an almost forgotten World War II tragedy.

A self-built castle made by a mysterious man.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

An urban laboratory.

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

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

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

A huge musical instrument played by the ocean.

The remains of a 12th-century chapter house in Golden Gate Park.

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

An overlooked and unassuming engineering marvel.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

A rococo retro-futurist future-rustic vernacular between yesterday’s tomorrow and the future that never was.

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

A storybook European village in Berkeley.

A private home built to resemble the shape of a microscopic creature.

The miraculous hydrant that saved the Mission District in 1906.