A monument to the man who almost killed Hitler.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

Hundreds of hidden passageways weave through the old quarters of Lyon.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Pluto is still considered a planet in Ithaca, New York.

In upstate New York, gorgeous waterfalls and a watermill are slowly being reclaimed by nature.

A unique underground structure dating back to the 1st century BC.

Walk through living pictures and music in the Cathedral of Images.

The lost Latin words were reconstructed using the holes from the nails that once pinned them in place.

A tribute to one granddaughter's old apartment which now represents the whims of each visitor.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

There’s a hidden military meme engraved on the World War II Memorial.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Look closely and you’ll notice that the color changes a third of the way up the tower.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The walls of the iconic dome are hollow and have a secret stairway.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.