The world's longest known cave system.

A key producer of charcoal iron in the early 1800s, the structure still stands today.

Everyone and everything one man ever loved and lost, now stare into the East for all eternity.

Kentucky's anomalous peninsula projecting into the Mississippi River, site of legendary earthquakes and local feuds.

The lowest point in the state of Illinois, at the confluence of the Mississippi and Ohio rivers.

An enormous natural sandstone bridge in Kentucky.

River pirates, murderous bandits, and serial killers used this Illinois cave as their debauched hideout.

Symbolic attempt to overcome the issues of life.

A turn-of-the-century architectural marvel built on healing mineral springs and salt licks.

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

The only freestanding table rock formation east of the Mississippi.

The chiseled jaw of this forgotten American hero still stands tall in a small Indiana town.

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

The world's largest anatomically accurate brain sculpture.

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

Even with only two residents and one building, this tiny Illinois town is famous for its burgers.

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

The legacy of an unsolved, gruesome murder rests beneath the spans of this historic bridge.

The multinational Burger King chain is banned from operating within 20 miles of a family restaurant filed under the same name.

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

Man-made geyser that rises to the exact height of the Gateway Arch.

A notorious Route 66 eatery once frequented by Al Capone.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Now nearly abandoned, Kaskaskia was once the capital of Illinois and one of the most important towns on the upper Mississippi.