This museum glorifies the humble potato.

Supposedly Satanic numbers adorn this preserved submarine sail.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

The world's first nuclear power plant is open to visitors looking to role-play a meltdown.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The site of the first battle of World War II.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

Fighting the British and making game shows for over 150 years.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

A bunker "with enough U.S. currency to replenish the cash supply east of the Mississippi" in the event of nuclear war now protects nitrate film.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

The only international border marker within the United States.

The site of a tragic massacre that spawned a multimedia franchise.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

Etched into a dry lake bed, this massive directional indicator is accurate without magnets.

Experience a quartz crystal sound bath inside a storied, all-wood sound-chamber.

Exotic feline breeding compound and conservation center.

The most unique castle in all of Southern California, entirely constructed from repurposed materials.

A regular looking rock with an unbelievable history.

This impressive tunnel was dug entirely by hand over the course of 36 years.