A lone gunner's station is all that remains of a replica Spanish Fort in Florida.

For 32 years the famous Ringling Bros circus troupe spent winters in this sunny spot in Florida.

Hidden inside one of the world's most well-visited zoos is a secret plaque promising eternal life.

Where the four original members of the Ramones hung out and revolutionized punk rock.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

This city park was once a lookout point for George Washington’s army during the Battle of Brooklyn in 1776.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

Collect holy water from a Bronx grotto.

A Gothic-style abode built to accommodate the church's three resident peacocks.

A crumbling staircase in upper Manhattan is all that remains of one of the most important sites in sports history.

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

Hiroshima survivor on Riverside Drive.

One of the few remaining American elm trees in New York’s Tompkins Square Park was the birthplace of a new religion.

This interactive gallery makes you feel like you've stepped into a fantasy world filled with whimsical monsters.

A sculptural commentary on capitalism pokes up from the East River.

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

This exemplar of modernist architecture is meant to captivate and inspire students of the Cooper Union.

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

Check out the underground party scene at the "Burning Man of Brooklyn."

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

The name of this tiny pocket park tucked between two buildings on Manhattan's Upper West Side is Latin for its location: "seventy-one."

Avoid gangster interaction while window-shopping.

A hidden "place of interment for gentlemen."

This collection of grinning ephemera has grown from basement to Brooklyn.