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

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

Behind a bodega is a small museum of relics and ephemera showcasing the history of New York.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

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

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

Become a prohibition rebel.

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

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

New York City's smallest piece of private property.

A semi-scholarly approach to sex.

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

Try not to get slimed in Tribeca.

Elevated freight railway turned wildly successful urban park.

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

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

A crumbling hospital from the 1850s on Roosevelt Island.

Approximately 250,000 people left homeless by the great earthquake and fires found shelter in Golden Gate Park.

Depicting scenes of everyday life - and specific individuals - in Great Depression era San Francisco.

Only hotel where you can legally launder money.

This 19th-century church is now a popular roller rink.

An art supply shop holds the secrets of this quiet neighborhood's raucous Barbary Coast past.