A 19th-century horse lover's bequest led to the construction of this unique fountain in Chicago.

Julia Buccola Petta's body was peculiarly well-preserved when it was exhumed six years after her death.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

A plaque marks a former safe house on the secret route, now hidden next to a McDonald's.

Pumpkin-like gargoyles and grotesques peer down from the rooftop of this unassuming apartment building in Illinois.

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

These abandoned grain silos and tunnels are an urban exploration dream.

An actual 1957 Cadillac De Ville, encased in 15 cubic yards of concrete.

Moving, mind-blowing metal sculpture work of an outsider artist.

A hollow cement depiction of time's inexorable effect on the human body.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

One of the few remaining relics of the meatpacking hub that made Chicago the "hog butcher to the world."

An avant garde art museum at the University of Chicago.

The final resting place of up to 6,000 Confederate soldiers, the largest mass grave in the Western Hemisphere.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

A historic hotel library in Indiana hides more than a few secrets on its shelves.

One of the first schools in the U.S. to admit students without regard to race or gender.

One of the largest collections of merchandise from the famous British sci-fi show can be found smack in the middle of Indiana.

Historians and hobbyists head to this former French outpost for the annual Feast of the Hunters' Moon.

An unknown number of cholera victims are buried in two nondescript graves.

This midcentury chapel is a bold architectural statement and a symbol of Indiana's Lutheran heritage.

This Indiana walk of fame honors music legends with record-shaped plaques in the pavement.

A concrete block embedded with thousands of pulled teeth was created by a local dentist to memorialize his dog.

A giant concrete egg marks this Indiana town as the "Egg Basket of the Midwest."