A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

A piece of John the Baptist in the American heartland.

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

A geological oddity formed by two rivers carving out a mass of limestone on both sides.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

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

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

Curious cave that stays a cool 56 degrees all year long.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

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

The palatial McDonald's that inspired Wesley Willis.

What was once one of the country's largest confectionary plants is now an abandoned ruin, but is still pretty sweet.

These Depression-era WPA sculptures have made a couple of stops over the years.

A source of civic pride, though the reason for its construction is unknown.

The oldest experimental corn field in America is still creating better ways to grow crops.

One of two identical monuments marking the sites of military training encampments in Peoria, Illinois.

A former atom smasher turned into an art gallery.

The only place in America where anyone who wants can shovel coal aboard an antique train.

A collection of 11 million buttons illustrates the human toll of the Holocaust.

This monolithic statue was erected in honor of Chief Black Hawk (even if it wasn't made to look like him).

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

The dream home of an iconoclastic renaissance man still stands as a monument to his domestically mundane vision.

Its eclectic exhibits range from the world’s first motorcycle to Luke Skywalker’s Land Speeder.

The first and only museum dedicated to stained glass and horology opened outside of Chicago in 2017.