Read between the lines of the subway map to find the hidden abandoned Civil War fort.

An illegally built ramshackle mansion tucked in the middle of Brooklyn is now being turned into condominiums.

Abandoned 19th century homes once occupied by naval officers, soon to be demolished.

Underground vaults of a former brewery beneath Brooklyn's Crown Heights are now used to ripen cheese.

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

Once a flowing stream and where the USS Monitor, the world's first ironclad, was built and launched.

Now owned by the National Park Service, this location was once home to illegal boxing matches.

This beautiful Brooklyn monument over a crypt memorializes a grim and largely unknown story from the American Revolution.

Residents of this Brooklyn neighborhood may be unaware their houses sit atop a buried trolley graveyard.

A mass grave for victims of one of the city’s worst fires.

The humble fort that saved Washington.

This neo-Gothic former auto showroom is one of the few remaining reminders of Brooklyn's "Automobile Row."

Known as the "Forgotten City" it was home to industry, riots, artists, squatters, and to one of the largest single disaster fires in New York City.

Final resting place for the Triangle Shirtwaist fire’s unidentified victims.

The gilded vestiges of a sterling department store can still be found in a Brooklyn shopping center.

A mysterious, abandoned building rotting on the Brooklyn waterfront.

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.

Waterway populated with abandoned projects, including a submarine.

The most unloved grain elevator in Brooklyn was a “Magnificent Mistake.”

19th century cemetery hidden in Brooklyn's Prospect Park.

A massive forgotten storehouse from 1913 on the Brooklyn Waterfront has a spectacular view of Brooklyn.

Take in a rare, face-to-face glimpse of Lady Liberty at this tucked away Red Hook park.

A way to take your secrets to someone else's grave.

Feral cats keeping the rodent population at bay all across Greenpoint waterfront.