What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

A once grand hotel is being retaken by the wilderness it once capitalized on.

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

Reforestation in action is the main attraction in this abandoned quarry.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

An unassuming island in the middle of the Hudson that hosts campers, including Aleister Crowley.

A peaceful international sculpture garden in upstate New York.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

For over 80 years, Mayan ruins stood proudly in a most unlikely location.

A nearly 100-year-old dining car in upstate New York embodies the golden age of roadside dining.

One man's swirling six-acre monument of stone.

Now the final resting place of prominent artists and musicians, it was originally founded to separate the rich from the poor in death.

The only intersection in America where the buildings on all four corners were built pre-Revolutionary War.

These lush botanical gardens employ the most purrfect pest control force.

A diorama of the Civil War, fought by cats.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

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

The Decoy Capital of the World.

This massive sycamore tree has been labeled as one of the largest in the state.

Although built to generate electricity for Marylanders, this dam has become an all-you-can-eat buffet for American bald eagles.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

A small museum along the Susquehanna River is home to a rich collection of Native American artifacts.

The home of possibly the least-loved U.S. president stands as a sort of unpopular Monticello.