Known as the "Cross At The Crossroads," this massive metal cross is just short enough to avoid the FAA.

A historic and oft-filmed prison stands in a Chicago suburb.

Fresh wooden posts have been added to ancient holes to recreate a primitive henge clock.

To find the "unicorns of the deep" you've got to go downstairs.

The mysterious white squirrels of this Illinois city are treated like sacred cows.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

These pretty kitties killed and ate as many as 135 railway workers.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

This now-deactivated naval base defended the Florida coast for centuries.

A historic presidential getaway on the continental United States' southernmost island.

An idyllic swimming pool tells the tale of Hemingway's trouble with women.

A building so large that it has its own weather.

One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Colloquially known as "the lynching memorial," this is the United States' first memorial to the victims of racial terror at home.

Designed by Maya Lin, the memorial honors 41 individuals who died fighting for equal rights between 1954 and 1968.

One of the few remaining examples of 19th-century London’s attempt to clean up its reputation.