The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

This bridge is haunted by the ghost of a distraught mother.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

A museum dedicated to the legacy of Bob Moog and his pioneering synthesizers.

Carrying on the legacy of a short-lived experimental school tucked away in the mountains of North Carolina.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

An eight-sided home built during a brief octagon craze in the 1850s.

A former Oz-themed attraction that has fallen into disrepair, but still holds some of the original magic.

Its original statue was deemed so ugly, locals called it “Scary Lucy.”

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

A living maritime paradox still floats in the same lake where it was built and resurrected... or was it?

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Huge abstract sculptures of the Puerto Rican Flag.

A chance to follow in the footsteps of the word's most legendary animator.

Pumpkin-like gargoyles and grotesques peer down from the rooftop of this unassuming apartment building in Illinois.

The famous author's birthplace is preserved in a town that he once described as narrow-minded.

Theater has had many different incarnations but has survived the ravages of time.

A display of magnificent stained glass windows is the first exhibit of its kind.

A Museum of Holography frozen in 1974.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

To find the "unicorns of the deep" you've got to go downstairs.

Years of archaeology, just chillin' by the water cooler.