A historic Black graveyard hidden in the parking lot of one of America's largest malls.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

Revolutionary War casualties fill the only 17th century structure remaining in Manhattan.

A museum collection honoring the long history of the FDNY is held in a disused Manhattan fire house.

Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

New York City's only preserved family home from the 19th century.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A crumbling hospital from the 1850s on Roosevelt Island.

The first evidence of some of the Earth's earliest life was found in this fossilized undersea grotto.

This lovely little pond is named after the hundreds of soldiers' corpses that were rolled into the waters during the French-Indian War.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

Where the Monitor was launched and ushered in the age of the "ironclads."

The rare American Civil War-era weapon was never fired in anger.

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

The humble fort that saved Washington.

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

The mass grave of a heroic Revolutionary War regiment sits below an empty lot near the Gowanus Canal.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The first American home of the isolated, egalitarian religion has a trove of Shaker architecture and artifacts.