The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Abandoned silver mine strewn with wrecked and twisted structures.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Claude Monet was baptized in this lavishly ornate Paris church.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

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

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

The "lovely red Vega" of the legendary record-settling pilot.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

Largest Roman Catholic church in North America.

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.

Over 600 acres of idyllic open grassland honor Nebraska’s georgic storyteller.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

This 13th century Gothic brick castle is the largest in the world by surface area.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.