4,000 monkeys used for medical testing on an island off of South Carolina.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.

This natural spring not only claims to heal the wounded but it has also been willed to God.

The oldest bridge in South Carolina may have been designed by the same man who created the Washington Monument.

An unfinished rail tunnel that has since been used to house cheese and bats.

At 238 feet above the bottom of a gorge this span is known as the biggest thrill on the road to McCarthy.

A museum devoted entirely to hammers has more than 1,400 items on display dating back to the Romans.

Buy your friend a drink or staple some cash to the wall for the next guy at the Salty Dawg Saloon.

The "Gateway to the Arctic" connects Barrow's indigenous population with the sea and its traditional industry: whaling.

This ghostly Alaska village still clings to a steep cliffside despite having been abandoned for over 50 years.

The ruins of this Alaska gold mine form a gorgeous ghost town.

This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

The ghostly remains of what was once the world's richest copper mine.

An auroral research program that superheats the ionosphere.

A trading post in the North Pole where children send letters.

This WWII-era military installation once held an entire city within its walls - now, its walls are falling down.

The king of U.S. high points towers over every other peak on the continent.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

The collection of 80+ pieces created between the years 1100 and 1500 is intended to be seen, heard, smelled, touched, and tasted.

The abandoned bathhouse is all that remains of the hot springs considered Florida's original tourist attraction.

This state park was once an important Native American cermonial center.

The smallest post office in the United States is no bigger than a broom closet.

The third tallest lighthouse in America once guided author Stephen Crane to safety.

Jacksonville's highways rendered this century-old grammar school unusable.