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

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

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

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

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.

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

A very classy 1920s-era bar right in Grand Central Station.

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

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

The "Seinfeld" diner.

A hip bar decorated with walls of golden skulls.

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

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

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

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

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

A terrific purveyor of natural history objects and curios.

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

A crumbling hospital from the 1850s on Roosevelt Island.