Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

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

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

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

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

This semi-hidden Manhattan restaurant is based out of a loading dock.

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

A simple midtown bar was once the home of a secretive and exclusive club staffed by "bunnies" under Hefner's strict rules.

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

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

This metal eagle one of the final remnants of a newspaper that wanted to keep Brooklyn to Brooklyn.

This curved Manhattan building was built to house the opulence of John D. Rockefeller's oil empire.

The one-time epicenter of American songwriting is now a little remembered Manhattan commercial block.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.

An easy to overlook storefront hides some of the most authentic and regionally diverse Chinese food in New York.

What happens here stays here – unless it affects the whole world.

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

This neo-Gothic former auto showroom is one of the few remaining reminders of Brooklyn's "Automobile Row."

One of New York's best collections of pinball is hidden in a secret bar in the back of this laundromat.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

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

New York's oldest and possibly grandest keeper of books.

A no-frills cinephile haven known for showing offbeat, underseen films.

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