An abandoned asylum where patients have been forgotten but their possessions remain.

This abandoned psychiatric hospital once housed more than 4,000 patients in the middle of a quaint New England town.

An abandoned asylum once on the cutting edge of lobotomies may be reborn as a Christian college.

This abandoned factory on the Hudson River once churned out a million bricks a week.

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

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

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

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

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

Glacial erratic or man-made dolmen? It probably wasn't druids.

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

Astonishing collection of helmets, scientific instruments, and medical models.

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

Small monoliths of several varieties of stone sit alongside a wooded path in the Bronx.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

A former connection to City Island, it has been abandoned since the 1930s.

The "Skinny House" is made from scrap, salvage, and a neighbor’s kindness.

The first pet cemetery in the United States.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

This dilapidated castle-like structure overlooks the Hudson River at one of its widest points and was once home to nuns.

Self-sufficient greenhouse floating on the Hudson River.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.