This historic hotel invented the chocolate brownie.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

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

This stately clubhouse has showcased German-American culture for over a century.

There are more than 4 million bricks inside this unofficial Lego museum in a former middle school.

This set of rickety spaceships are prepared to give alien travelers a place to relax and go to the bathroom.

The oldest bar in Missouri is hidden within a limestone brewery cellar more than 50 feet underground.

Undone by Prohibition, this abandoned brewery-turned-flour mill is now ready for its third act.

This mosaic-covered bar is brimming with curated curios.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

An abandoned factory along the Mississippi coated by a giant mural.

This majestic tree has survived 400 years of storms, droughts, and floods, and is a beloved natural landmark in Missouri.

An abandoned concrete jungle surrounded by a lush park.

This historic motel standing at the "crossroads of America" offers a radio in every room and was saved by local protesters.

The maximum security facility was once thought to have "the bloodiest 47 acres in America."

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

Erosion and time have created a naturally-formed water park.

This abandoned prison castle has become an imposing gallery of graffiti art.

Less a museum than a bizarre fantasy world created by artists and engineers.

Once a bustling cotton factory, this early 20th-century building is now home to a thriving artspace.

Once one of the largest producers of pig iron in the world.

Famous for its bio-luminescent inhabitants, known as "Dismalites" .