The only fully-realized skyscraper built by the famed American architect, Frank Lloyd Wright.

This arcade is one of the last places to catch a public performance by the now-defunct ShowBiz Pizza's house band of animatronic animals.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Mile-long cave system near Great Smoky Mountains.

Before TV meteorologists, there were weather kiosks. This may be the last one in the United States.

The world's largest version of this iconic puzzle cube is located in Knoxville, Tennessee.

The secret city built by the Manhattan Project.

Although it has never been a secret ninja base, this shrine still has plenty of tricks up its sleeve.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

An ancient monastery, a locked room, and a mysterious book heist.

A once-luxurious, now abandoned hotel in the Italian Alps.

Stuck in a bygone era, the oldest subterranean shopping street in Japan hides beneath the popular Asakusa district of Tokyo.

An electrifying collection of gadgets and literature from the 16th through 20th centuries.

Like your grandma's attic—if your grandma were a little weirder, extremely well-traveled, and had a great eye for art.

This Art Deco masterpiece has stood in for some of the most famous buildings in comic book history.

Tour the original street level of Port Angeles, buried underground in 1914.

The wreckage still sits at the exact spot the plane crash-landed in 1945, carrying 1,000 pounds of explosives.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

A book collector's dream, this Toronto bookstore has the world's first "Biblio-Mat," a random book vending machine.

European castle ruins in an American state park are actually the product of death and grief.

Calidum et Deliciose Succosum!

This abandoned mining village was predicted to resist decay longer than any other modern human settlement.

A statue of the heroic plumber stands outside a company that bluffed its way into being Nintendo's Scandinavian distributor.