Exact replica of the ancient monument, but much, much lighter.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

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.

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

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

A local prank turned town icon.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

There aren't too many operational funiculars around, but Pittsburgh has two!

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

Ruins of a once-prized railroad station in New York.