The secret city built by the Manhattan Project.

An ode to "The Queen of Appalachia."

An abandoned town is hidden in Great Smoky Mountains National Park.

Soaring over the Niagara Whirlpool since 1916.

An ancient fortification lives on in this Chinese city.

Although resembling a grand Buddhist temple, this structure is actually the largest mosque in China.

The best place for scenic views of the DMZ and North Korea.

South Korea's largely symbolic, barely used gateway to the North.

Secret North Korean passage discovered below the world's most dangerous border.

A monument to the two U.S. officers killed by North Korean troops while trying to trim a poplar tree.

The site of many tense prisoner exchanges across the Military Demarcation Line between North and South Korea.

Breathtaking and huge 430 year old maps of Italy.

The celebrated eyesore created by starry-eyed sweethearts.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

In Paris, Texas they have their own Eiffel Tower, it just has a cowboy hat on it.

The world's tallest statue of an American hero.

The "world’s largest honky-tonk" also has its own indoor rodeo arena.

Belly up to the bar in Cowtown, don't forget to buy some boots.

A castle built by an eccentric medieval enthusiast in suburban Ohio.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.