The water in this preserved area spawns vegetation that gives it a deep green color.

World's smallest skyscraper, the product of a remarkable con.

The Grand Canyon of Texas.

A pair of giant legs paying homage to a poem, a king, and it would seem, socks.

These half-buried combine harvesters just off Route 66 are an homage to the Cadillac Ranch.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

This too-low North Carolina railroad trestle is still a notorious big rig executioner.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

This museum explores the grim reality of life in the earliest British colonies in America.

This estate on the banks of the James River was home to a Founding Father, two presidents, a famous bugle melody, and what some say was the actual first Thanksgiving.

The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

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

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

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

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

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

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

Perhaps the most scandalous statue of America's first president.