A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

Odd outsider art installations surround a Gold Rush-era ghost town.

Go inside to really appreciate this 500-year-old technological masterpiece.

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

A 30-year-old Sycamore tree grown from a seed taken to the moon and back.

This spectacular track has run continuously since 1882.

The largest burial mound in the United States holds the remains of prehistoric West Virginians.

The world's first aircraft factory has been hiding inside an automobile plant for almost 80 years.

The inventor of a number of hybrid corn species is immortalized with a field of giant corn.

The largest ancient burial mound in Ohio.

This bridge uses an inverted bowstring truss and is believed to be the only of its kind in the United States.

This old-fashioned carhop restaurant gave the world the waffle cone.

This kitschy tavern is also home to rare early editions of "Treasure Island."

A giant knight, sex education, date shakes, and Jesus coexist happily in this Coachella Valley desert oasis.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

Lovingly nick-named the "Brick Dick" this municipal tower was winner of the World's Most Phallic Building Contest.

The 80-foot tire that looms over Michigan's I-94 was once a Ferris wheel in the New York World Fair.

Priceless space junk on display in front of a local Dairy Queen.

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

A sharp sculpture made of thousands of pieces of jagged glass.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

Small teepee-like houses built for TB patients have become sheds, studios, and bus stops around Colorado Springs.