In this case, 'zero' marks the spot where the iconic Old Spanish Trail ends.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

The man who wasn't there.

A trio of colossal statues spread across a Dallas neighborhood chart the emergence of a giant robot born of a locomotive and spilled gin.

Hidden within a spa in a Texas strip mall is a restaurant specializing in Eastern European foods.

A visionary, futuristic sculpture in Los Angeles that never met its extraterrestrial potential.

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

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

This kitsch eatery is chock-a-block with bric-a-brac.

Steinbeck's old stomping grounds, immortalized in Cannery Row.

The oldest U.S. Government building in California, and it's State Historic Landmark #1.

One of the most elaborate displays of Jellyfish is on display at the aquarium.

A tree grown from astronaut seeds which were exposed to cosmic rays.

Visitors can swim with vicious predators in Crocosaurus Cove's plastic daredevil enclosure.

South Korea's largely symbolic, barely used gateway to the North.

The best place for scenic views of the DMZ and North Korea.

Secret North Korean passage discovered below the world's most dangerous border.

The only castle in North America to ever house European sovereigns.

A museum glorifying the life of Stalin, located in the city of his birth.

Ancient rock-hewn town that witnessed key events of Georgian history.

Underground monastery and fortress.

Unusual building appears to be haphazardly built from randomly piled bricks.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.