A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

The façade of this building looks like a bingo board, but it's really a giant clock by a famed graphic designer.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

Manhattan's Thirteenth Avenue was made on landfill then deliberately destroyed — apart from one small, obscure block.

Established in 1937, the oldest candy shop in New York City boasts a rainbow-colored inventory that would make Willy Wonka envious.

This study room in the New York Public Library saw the creation of one of contemporary America's greatest traitors.

The former home of the reclusive "Weird Wendels" who dominated New York real estate a century before Donald Trump.

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

Walking around West Harlem reveals a scavenger hunt of beautiful bird murals.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

A trove of century-old litho stones from the Puck Building's printing days were discovered behind a cellar wall, and are now hanging in the store.

There are owls with glowing eyes in Herald Square.

Phil Mortillaro uses keys to bring art back to the Village.

Come for the waffles, stay for more waffles.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

Long the exclusive domain of birds and vagabonds, this little-known Central Park peninsula is open to the public once more.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

New York City's smallest piece of private property.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

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

The home of the first American-born saint is one of the only curved buildings in New York.

A plaque immortalizes the spot where the early American spy said his famous last words: "I only regret that I have but one life to lose for my country."