Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

Thousands of jack o'lanterns light up Halloween at this historic West Virginia home.

This mansion turned restaurant was once a pitstop for Al Capone during his travels.

This homegrown adoption center offers a wonderland of feline companionship.

Live long and prosper in Tennessee.

Walk the whole Mississippi River!

This head-spinningly bizarre Depression-era art cave is wall-to-wall quartz and Jesus.

Visit this playground of waterfalls, caves and sinkholes.

Enormous lake at the bottom of a unique cave system.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

You thought Santa Claus didn't exist, but it turns out you were wrong.

A lesser-known part of the Kinsey Institute is this impressive collection of art, artifacts, and material culture related to human sexuality.

A rural hall of justice holds the world's only comic book and superhero museum.

Ornate limestone building now filled with geologic specimens, and more.

Ruined pieces of stone and a swimming pool are all that remain of an amusement park swept away by a flood.

This candy shop has been serving up sweets to the Louisville area since the 1850s.

The site of a 19th century "dream city" that almost rivaled Chicago before being swallowed by the Indiana sand dunes.

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

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

A flamboyantly decorated bridge signals diversity and fellowship at the entry to Indianapolis' Broad Ripple Village.

Once adorning a New York skyscraper, these reclaimed ruins now haunt an Indiana park.

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

This strange example of the Egyptian Revival architecture trend now holds Mardi Gras floats.

A pink cottage covered in hearts served as a haven and a resting place for LGBTQ activists.