The bright red stripes streaking across the rocks are the star feature at this Icelandic waterfall.

A sulfuric martian landscape that looks far better than it smells.

This elegant arc of a waterfall marks a religious turning point.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

Giant granite rocks standing end-to-end like a train of circus elephants.

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

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

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

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

The world's second largest rocking chair is found on Route 66 in Cuba... Missouri.

European castle ruins in an American state park are actually the product of death and grief.

The longest of the four remaining covered bridges in Missouri.

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

An abandoned concrete jungle surrounded by a lush park.

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

A half-size replica of the World Trade Center towers above Tulsa.

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

Four, 18-foot-tall badminton shuttlecocks lie scattered about the lawn of a Kansas City museum.

The first car-centric shopping plaza in the U.S. brought a little bit of Spain to downtown Kansas City.

The oldest liquor store in the country is a model of resilience and mischief.

Once the most flame resistant building in the country, the South Carolina Historical Society building was almost burnt down in a fire.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

The fifth tallest statue in the United States is a shirtless monument to the oil worker.