Eons ago, a rushing lava river formed this pristine passage through solid rock.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

There are owls with glowing eyes in Herald Square.

A terrific purveyor of natural history objects and curios.

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

This 19th century jail was mainly used to incarcerate the drunk and disorderly.

A futuristic temple of light uses prisms and rainbows to create an atmosphere of peace.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

Limestone caves with spectacular showcase chambers.

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

A clear blue swimming hole with hidden caves, still unexplored.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

The prototype for all Nazi concentration camps.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.

Breathtaking and huge 430 year old maps of Italy.