The only known Futuro house in North Carolina sits along a stretch of desolate highway on the Outer Banks.  .

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

This Transylvania County city is home to a rare white squirrel population that is descended from an escaped carnival animal.

A curious collection of oddities including a lock of Alexander Hamilton's hair and Harry Houdini's ouija board.

A retired tobacco farmer's pet project turned into a sturdy miniature city.

A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

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?

These eerie outliers of the lightning bug family glow a mysterious blue color.

A sculptor's dream castle turned fantastical ruin.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

Shocking dioramas of human torture, meant to promote human rights awareness.

The ruins of an ancient city built by Mayan traders is centered around a temple of a sacred feathered serpent deity.

Incredible sculptures inspired by obscure passages from the Bible.

A collection of fading fantasy tchotchkes lines this dirt road in the Colorado wilderness.

The remnants of an early American attempt at missile defense.

A grassy pyramid named after a French battle.

A huge stone pyramid built for fun.

North Korea's massive "hotel of doom."

Iconic pyramid from famed British architect Norman Foster designed to represent all of the world's religious faiths.

A folly built to satisfy a gentleman's bet that he could drive his horses through the eye of a needle.

This burial pyramid in central Ireland is thousands of miles and thousands of years away from its Egyptian inspiration.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.