A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

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

This monument to a veteran of the Mexican-American War is one of only two in Manhattan that serve as an actual mausoleum.

Elevated freight railway turned wildly successful urban park.

The notorious headquarters of a corrupt political machine.

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

New York City's only preserved family home from the 19th century.

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

Plot your trip through the city on the sidewalk.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

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

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

Possible relics of the ancient Roman city are hidden in this restaurant's façade.

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

Try not to get slimed in Tribeca.

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

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.

Less a museum than a bizarre fantasy world created by artists and engineers.

The sister plane of the C-123 shot down during the Iran-Contra Affair has found a new purpose in retirement.

Costa Rican accommodation resembles a crash site, but with a nice balcony.

At 207 feet, one of the world's longest continuous escalators.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.