Why have you never heard of the second most popular tourist site in New York?

Home to the abandoned Tioronda Hat Works Factory, this park is a combination of woodlands and marshlands.

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

A long abandoned hospital building on the outskirts of NYC.

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.

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

Underground tunnels remain beneath this abandoned mental asylum.

In the power of this waterfall, Alexander Hamilton saw the potential for industry.

Yo, Adrian!

A beautiful, historic location open to the public.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

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

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

A collection of haunted artifacts chronicles the career of the world’s most famous paranormal investigators. Museum is temporarily closed with plans to re-open.

Visit the grave of America's most prominent paranormal investigators and self-proclaimed demonologists.

Haunted Victorian house that inspired a legendary "Ghostbusters" court ruling.

This giant rock arrived at this quiet park thousands of years ago on the back of a massive glacier.

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

Eccentric concrete mansion and museum designed and built by hand from the inside out.

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

A castle inspired by medieval architecture is hidden in the woods of Connecticut.

This mouldering abandoned mental hospital was once a center for progressive healing.

An extraordinary collection of vampire-themed antiques lurks on the second floor of a store.

This tiny New Jersey village has lived many lives but seems determined to remain a ghost town.