A throwback train ride transports passengers through one of the lesser-known national parks in the country.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

An abandoned asylum incorporated into a college campus.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

The fifth-longest natural arch in the world, and the longest outside China.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A tunnel with windows, so you don't miss out on the impressive views.

The Grand Canyon of Texas.

The first KFC is on the National Register of Historic Places.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

The last remnants of Fort Pitt also hold the distinction of being the oldest structure west of the Allegheny Mountains.

A beautiful Victorian-era cemetery, complete with a miniature village.

No one really knows how these old hobby horses got here, but the herd keeps growing.

The railroad tunnel nicknamed the "Bloody Pit" for taking the lives of hundreds during its construction.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

One of the most scenic falls in Massachusetts has a history of death and grim legend.

A stone monument marks the location of the final battle of an armed uprising which had a significant impact on the creation of the US Constitution.

The site of the first "historically true" UFO encounter in the U.S.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.