Cryptic messages embedded in the New York City sidewalk.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Wine bottle sculpture with a ship's stateroom inside.

A hidden "place of interment for gentlemen."

Plot your trip through the city on the sidewalk.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

Walk over a 150 year old manhole.

The "Seinfeld" diner.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

Peek through the gates at this oasis from the city, full of Old English charm.

A hands-on traveling collection of the innovative devices of yesteryear.

Mysterious 500-year-old tapestries depict a unicorn hunt.

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

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.