NYC's legendary underground network for bovine transportation.

A whimsical, but often overlooked clock in Park Avenue.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

Unrepaired walls from a 1920 anarchist bomb attack.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Commemorating the spot where the famous scientist fed his pigeons.

A bit of retro transportation flair preserved in the world's largest department store.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

The former hotel where Tesla invented the radio.

Visit the monolithic tomb of America's most famous general.

One of the last Jazz Age "Wonder Theaters" in New York City.

Avoid gangster interaction while window-shopping.

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

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

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

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

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

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

An unassuming secret door once led to a legendary watering hole.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

New York City's smallest piece of private property.

A dilapidated dock tells the story of Titanic's missed arrival.