This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

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

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

A monument celebrating the idea of reaching inaccessible places.

The most decorated dog of World War I is preserved in the Smithsonian.

Home to items never before seen by the public.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

Once America's tallest structure, now a Baltimore landmark.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

A museum dedicated to exhibiting remarkable outsider art.

This free, take-a-book shop seems like a trick but isn't.

World War II bunker still standing on the New Jersey beach.

Step inside Lucy, the world's largest "elephant."

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The land is home to swimming ponies and a legendary 18th-century treasure.

The trials and tribulations of marking Poe's grave.

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.

When ecosystems collide in the arid Southwest.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.