Naturally formed white marble arch housed in an abandoned marble quarry from the 1800s.

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

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

This abandoned neighborhood is now a park filled with beautiful trees, wildflowers, and hints of its past.

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

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.

Stay at this storybook estate, featuring Sir Henry Hudson Kitson's masterpiece "Gingerbread House."

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

A man used his Civil War-era fortune to build this sanctuary in memory of his wife.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

Three acres of mythology-inspired sculptures are visible from the highway.

A memorial to Chinese freedom in the city where American freedom was born.

Protecting the future of some of the rarest and most misunderstood mammals of North America.

This hidden labyrinth offers walkers some brief peace of mind.

The life of one of FDR's possible mistresses is preserved in her palatial Hudson Valley mansion.

This picturesque Victorian ghost town was once a thriving mill community.

Hundreds of numbered stakes hidden in the woods mark the graves of the lost souls of a nearby asylum.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

This abandoned cemetery is crumbling into ruin, exposing the artifacts and bodies buried there.

The highest point in the state of New Hampshire, and while unlikely "the worst weather in the world," it sure seems that way to hikers.

The final resting place of the man who played the Invisible Man.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

The walkable ruins of an 19th century hotel, destroyed in a horse cremation gone wrong.