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

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

These ornate manhole covers were used for a now-forgotten purpose.

Townhouse facade doubles as an RMS Titanic Memorial.

The phone booths of New York City have all but disappeared, but their remains were once found in this "graveyard," sadly now removed as well.

An accidentally hidden library containing the ephemeral history of New York.

Walk over a 150 year old manhole.

The only subway station in the city that still makes use of gap fillers.

An art installation commemorates journalist Nellie Bly's undercover reporting inside a New York asylum.

The lesser-known Alice sculpture of Central Park dedicated to the “godmother of American children.”

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

An aptly-named street near the birthplace of the modern LGBT rights movement.

A 19th-century politician who died after walking home in a blizzard is honored with this Manhattan statue.

This monument to a veteran of the Mexican-American War is one of only two in Manhattan that serve as an actual mausoleum.

Nope, not Washington Irving's house.

The home of one of America's most beloved fictional characters has become a real world landmark.

Fake subway tiles were installed to cover a design that resembled the Confederate flag—it's unclear if the resemblance was intentional.

A large boulder marks the place where the island of Manhattan was purportedly "sold" to the Dutch.

This Upper East Side apartment co-op was designed as a tuberculosis sanitarium.

This simple Manhattan salt house is artfully shaped... well, like a giant granule of salt.

Currently housing a corporate bank branch this building at the southern tip of Manhattan was once the gateway to luxury vacationing.