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

The first American department store, and home to the largest operating musical instrument in the world.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

A former plant in one of the hubs of U.S. steelmaking has been turned into this museum celebrating the history of American industry.

The oldest surviving botanic garden in the United States.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

This remote island in Iowa was abandoned after being devastated by flood.

In which a local geological marvel becomes a quaint roadside attraction.

Mysterious rocks that ring musically when struck.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

An abandoned stretch of highway, deteriorating next to the operational one.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.