This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

One kilometer of thick brass rod laid out before your eyes.

The greatest real estate coup of all time.

A terrific purveyor of natural history objects and curios.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

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

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

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.