This 5-by-6-foot wooden hut is the smallest historic post office in the U.S.

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

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

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

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

This legendary "evil" doll has been haunting the citizens of Key West for over 100 years.

Arrr! The most authentic collection of pirate artifacts in the world... matey.

Meet manatees face-to-face at this zoo for native species.

One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.

One of the world’s largest and deepest freshwater springs, where mastodons once roamed.

This now-deactivated naval base defended the Florida coast for centuries.

Ruins of an old sugar mill sitting quietly next to a park in rural Florida.

These mysterious ruins are hidden amid this sleepy coastal city.

The museum chronicling a treasure hunter's dream, fulfilled.

Tucked away in the forests of North Florida resides a 19th-century lighthouse.

The bottle house obsession struck a Florida man in his retirement, and now he can't stop building.

Home to the only outdoor municipal elevator in the United States.

A sprawling cave network created by a lone lava tube.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.

World's largest porcine hairball sits in a collection maintained by Benedictine monks.

The first North American landing spot for James Cook on his third voyage of discovery in the Pacific.

A Roman-style column in Oregon hides a spiral staircase inside.