Lines from a walking song are etched into a rock in Natural Bridge State Park.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

The longest and widest floating bridge in the world.

In a quiet north Chicago neighborhood rests a stunning relic of the golden age of earthenware design.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

A building so large that it has its own weather.

A tribute to Ponce de Leon's supposed quest for eternal youth.

A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

An office built to look like a giant basket.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

An enormous goose sits atop this nest-shaped home.

This abandoned cemetery has a dark past of bodies buried over bodies.

A real flying saucer, contracted by the U.S. Air Force.

The world's first aircraft factory has been hiding inside an automobile plant for almost 80 years.

A headstone tells the sad story of a lost little boy and his pet dog.

The largest earthwork effigy in the world.

Now in disrepair, this 19th century station was a stop on of the famed B&O Railroad.

A castle built by an eccentric medieval enthusiast in rural Ohio.

Where beautiful signs live on forever.

Prison made famous by The Shawshank Redemption has been out of commission since 1990.

What is it about mushrooms that makes people wish they lived inside of them?

This humble star-gazing center touts itself as the "Birthplace of American Astronomy."

This magnificent Cincinnati graveyard is also a popular public park.

This open air cathedral invites all faiths to worship under the only roof big enough to fit them all: the sky.