Ruins of a once-prized railroad station in New York.

The last remnants of what was once one of the world's grandest hotels can now be found in a Manhattan subway station.

This curved Manhattan building was built to house the opulence of John D. Rockefeller's oil empire.

"A hideous albatross in the Hudson River Valley."

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

Visit the site of a subway powered by nothing more than air--and lots of it.

A staggering collection of photographs depicting medical, social, and historical change.

The site of William McKinley's tragic assassination is only marked by an underwhelming boulder.

This restored house is like a time capsule of the president's unconventional inauguration.

Buffalo's abandoned concrete grain elevators are getting a second life.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

The library of every book lover's dreams.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

Spinning silently in the lobby of an Art Deco masterwork is a massive vintage model of the Earth.

This abandoned subway station can still be seen on regular commuter trips.

The walls are decorated with whimsical murals painted by the creator of the Madeline franchise.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

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

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

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

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

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

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