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

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

The site of Neil Armstrong's first flight is marked by a full on replica of the moon landers.

Colloquially known as "the lynching memorial," this is the United States' first memorial to the victims of racial terror at home.

The country music legend's grave is surrounded by Astroturf because fans kept plucking out the grass.

Cadillac where country's first big star was found dead.

Designed by Maya Lin, the memorial honors 41 individuals who died fighting for equal rights between 1954 and 1968.

The former home of the hard partying literary power couple is now one of the only museums devoted to their story.

It took more than 20 years and a sharp eye for one man to assemble this quirky collection.

Inside this wonderland of weird, visitors are treated to a collection ranging from skeletons to haunted artifacts.

Walk through row upon row of manicured miniature trees at the United States' largest bonsai nursery.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Wall to wall taxidermy at Denver's oldest and most exotic steakhouse.

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

The arch that celebrated the completion of the Lincoln and Victory highways.

One of corporate America's best-kept secrets is also one of the most publicly displayed.

This public baseball field is a beloved remainder from of one of the most historic stadiums in the country.

This small museum gives visitors a chance to soak up the history of the "sponge capital of the world."

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

Huge masonic hall in Philadelphia with lavishly themed rooms.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.