An abandoned 1970s theme park that has been turned into a space for waterfront walking.

The NASA scientists behind Apollo 11 started out developing Nazi weapons at this abandoned German rocket factory.

This 1960's Soviet submarine in Peenemünde Harbor claims to be the largest submarine museum in the world.

This incredible stone temple is a monument to death, victory, and fantasy architecture.

This small exhibition displays equipment and artifacts once belonging to the feared Stasi secret police.

This lighthouse has been guiding shipping into the Golden Gate since before the American Civil War.

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

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

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

Faceless white figures loom over the city from the rooftop.

A shining, cold, black organ lies in San Francisco's financial district.

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

Chevron maintains one “Standard” brand station per state so it doesn’t lose the trademark.

This 19th-century church is now a popular roller rink.