Nikola Tesla's former home contains an homage hidden from plain sight.

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 semi-scholarly approach to sex.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

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

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

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

Try not to get slimed in Tribeca.

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

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

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

A crumbling hospital from the 1850s on Roosevelt Island.

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

A terrific purveyor of natural history objects and curios.

One man's homage to the sun continues to grow like a glass fractal.

Shop selling 500 flavors of soda has something for everyone.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

America's most famous piece of self-built architecture.

The legendary building that needed ghostly approval before being built.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.