Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

A propulsion engine testbed that paved the way for the Space Shuttle launch sits without recognition at this rocket center.

It may look like no more than a full-scale model, but every part of this full Space Shuttle stack had a working role in aviation history.

This 880-acre facility is home to a massive collection of vintage motorcycles and cars, as well as a 2.38-mile race course.

These ruins are all that's left of the former Alabama State Capitol.

Striking natural chalk bluffs that rise dramatically along the Tombigbee River.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

Anne Rice, one of the most influential writers in gothic literature, is buried alongside her husband in a New Orleans cemetery.

An abandoned town is hidden in Great Smoky Mountains National Park.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

Supplies are schlepped up by llamas at this century-old inn, accessible only by hiking trails in the Great Smokies.

Over 20,000 sets of spice shakers reveal the surprisingly telling history of our most basic spices.

This abandoned ironworks was once the most important military supplier in America.

The remains of the furnace and iron works that produced the massive Hudson River Chain still stand in the woods of New York.

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

A 19th-century blast furnace that played a big role in the area’s industrial development.

Once the home of a noted Civil War spy, the two-story brick house now serves as a museum.

A 1,000-foot-long railroad tunnel under Shavers Fork connected the towns during West Virginia's logging boom until its closure in 1985.

The first burial place of the Harmonist Society, a utopian community for which the surrounding town of Harmony is named.

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

The site where nine miners were trapped underground for over 77 hours in 2002.

Pennsylvania's own Roswell-style UFO mystery.

At almost 1,000 years old, this is the oldest known door in all of Britain.

The niches over the western entrance of Westminster Abbey honor individuals from the 20th century who gave their lives for their Christian beliefs.