A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

The oldest surviving presidential residence in the United States.

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.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Once home to more than 50 displays of freshwater fish.

The massive machine creates cracking displays of indoor lightning.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

A young state senator's deathbed plea to be buried inside a rock resulted in this unusual grave site.

Down the road from where the Wright brothers lifted off is another flight tribute practically hidden from sight in the woods.

The humble horn finally finds a place in the sun.

This too-low North Carolina railroad trestle is still a notorious big rig executioner.

This handcrafted, old western-style town is filled with deserted cars, retired movie props, and other forms of Americana.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

Divinely-inspired village houses 6,000 dolls, plus strange and lovely outsider art.

Andy Griffith's hometown has made itself up to look like the fictional town of Mayberry.

These strange large stones served as a campsite and lookout post for generations of Native Americans.

Ruins of an American Civil War iron forge still survive today.

This nine-story building can be played like an instrument.

A historic covered bridge, only one of two remaining in North Carolina.

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

This high point in the Great Smoky Mountains is said to be home to the chief of all bears.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

A smaller model of the Da Vinci sculpture that took 500 years to come to life.