Are they the remains of a fallen hotel, or the final stronghold for escaped Nazis?

The island houses the ruins of a secret nuclear fusion lab that once employed high-profile Nazi scientists

A massive, secret marina for the Nazis' most formidable weapon in the Atlantic.

Launch site for nuclear war against Western Europe.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A mud statue stands in the dark tunnels, seeming to hold up the weight of the city above.

This rusted shipwreck directly in front of a century-old abandoned lighthouse looks almost surreal.

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

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.

This Scottish bridge seems to compel dogs to leap to their death.

Henry Ford's failed rubber plantation in the middle of the Amazon rain forest.

This massive subterranean fissure is known as the "underground Grand Canyon."

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.

This cramped crevasse saw the entire population of its island suffocated inside its depths.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Medicinal spa created with the discharge from a geothermal energy plant.

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

Fifty years of contamination in Scotland's waters.

On this stunning Scottish island, you can walk in the footsteps of dinosaurs.

This life-size monument honors the legacy of a famous literary feline.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.