The NYC subway system is massive, and not too surprisingly there are large sections of this system that are not publicly accessible.
Everyone already knows about the abandoned stations, but lesser known are the abandoned and closed mezzanines and entrances that dot the system. Many were closed due to low usage and crime prevention – creating a left over taint from the ‘bad old days’ of NYC.
Here at East Broadway on the F line, one can find a full length mezzanine above the station platform. Part of it was tiled and used in passenger service, while the rest was left unfinished – perhaps originally intended for maintenance use.