In upstate New York, gorgeous waterfalls and a watermill are slowly being reclaimed by nature.

Once America's longest-manned military fort, now an abandoned hulk.

A natural gas leak provides a flickering flame beneath a waterfall.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Oldest surviving example of a Dutch saltbox frame house in America.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

A 19th century hat factory still stands as a crumbling ruin in upstate New York.

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

The real-life site of Ichabod Crane's infamous gourd attack.

This tiny church near Sleepy Hollow contains Henri Matisse's last work, a rose window, and nine windows by Marc Chagall.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

An abandoned 19th century quarry in the middle of the woods, remade by unnamed wanderers into a massive series of rock thrones.

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

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

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

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

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