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

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

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

One of only two commuter aerial tramways in the United States.

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

From scholastic to sepulchral - now under reconstruction.

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

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

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

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

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

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

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

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Elevated freight railway turned wildly successful urban park.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

During the holidays, a vintage subway train whisks New Yorkers back in time.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

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

Tucked in the back of this amazing antique store is an important piece of medical history.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.