A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

The longest navigable underground river in the United States is home to countless blind and albino animals.

The history of funerals and funerary customs.

In Chicago, a pizza-enthusiast has opened a museum dedicated to the history of pizza.

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

Built in 1869, this now-retired structure looks more like a medieval fortress than a county lock-up.

A 30-foot man on a penny-farthing bicycle rides along the banks of the Mississippi.

Its eclectic exhibits range from the world’s first motorcycle to Luke Skywalker’s Land Speeder.

This family driveway also serves as the highest point in Illinois.

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

The clothes-washing king doubles as a community center with some unusual features, including an aviary filled with finches.

This historic lavatory leftover features two levels of defecation stations completely without context.

This cemetery is all that remains of a school for "wayward" girls.

The hometown of Popeye's creator is littered with a growing collection of granite cartoon characters.

Today this bizarre rooftop phone booth seems like a piece of kitsch but it was once used to spot disastrous storms.

This life-size bronze statue remembers the tallest recorded human in his Illinois hometown.

In the loving memory of a tragically deceased role-player this Illinois park is decked out with both dungeons and dragons.

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

Spanking machines, fake goats, and more devices of humiliation are on display in this museum of fraternal initiation devices.

Assemble a masterpiece at the first and only North American school exclusively dedicated to mosaic art.

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

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

The world's largest collection of the world's largest objects is in one small Illinois town.

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