Park Avenue in Manhattan is one of the most well-known avenues in New York City, as it is home to iconic structures such as the Waldorf-Astoria, the Pan Am building, and Grand Central Station. However, many New Yorkers may not know that they can also find a hidden train track, the Seventh Regiment Armory which became a cultural institution, and a Founding Father’s pistol along Park Avenue as well. Here are ten secrets about Park Avenue to keep in mind the next time you find yourself in the area.

10. Park Avenue was Fourth Avenue in the Original Commissioners Plan of 1811

Commissioner's Plan 1811-Map-NYC-Library of Congress-005

Today, the portion of Park Avenue that is above 14th Street is only known as “Fourth Avenue” from 14th street to Cooper Square. In the original Commissioner’s Plan for New York City, however, the street was named “Fourth Avenue” all the way up to Fordham Road in the Bronx. A stretch of the avenue from 34th to 40th Street was renamed “Park Avenue” in 1860. Then, in 1959, the area from 33rd street to 17th Street was named “Park Avenue South.”