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

All that's left of the quintessential "cabin in the woods."

One of the most powerful computers in the world can be visited by anyone who wants to experience more computing than they can handle.

Enormous lake at the bottom of a unique cave system.

A bizarre roadside attraction and the first instance of miniature golf in the world.

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

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

The secret city built by the Manhattan Project.

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

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

A failed utopian experiment for British expats in the American South is now a Victorian village frozen in time.

Bananas are often left for the first monkey America ever recovered alive after being launched into space.

All you ever needed or wanted to know about America's favorite whiskey, but not a drop to drink.

Home of an evil witch famous within southern folklore.

The first full-scale tunnel built in America is short but scenic.

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.

You have to love a museum with a truly dedicated focus. A focus on Superman, for example.

Over a dozen Native American earth mounds dating back over 2,000 years dot this Tennessee archaeological park.

This Tennessee museum is dedicated to a tragic railroad hero who inspired the famous ballad that bears his name.

A whimsical folk art garden full of punny pieces and a diorama containing 3,500 toys.

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

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

An enormous natural sandstone bridge in Kentucky.