To find this cache, you must complete the nearby adventure lab cache "Beautiful Branch Brook Park". The free app can be downloaded to your phone or log in here: https://labs.geocaching.com/login
The final location is a fun bonus to the adventure lab walk, and you can learn more about this structure here: https://www.bridgesnyc.com/2014/12/branch-brook-park-subway-bridges/
Use this and the clues from the adventure lab to solve for the final location.
N40° 45.2AB’ W074° 11.CDE’