The "Seinfeld" diner.

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

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.

Unique antiquarian shop specializing in globes, maps, and prints.

Nondescript elevator doors open to reveal a stunning, surreal world.

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

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

Ride the subways of yesteryear.

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

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

A hands-on traveling collection of the innovative devices of yesteryear.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

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

Elevated freight railway turned wildly successful urban park.

New York's oldest magic store.

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

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

The train engine is tucked under an apartment building on a quiet Tokyo street.

Statue in Salem of the woman who starred as the witch Samantha in the sitcom "Bewitched."

The lecture hall where Alexander Graham Bell first demonstrated the long-distance phone call.

"Try not to knock anything over!"

One man’s hobby is another man’s world of metal wonders.