9. DPW 1874
This DPW Sewer manhole located on Amsterdam Avenue near Columbia University has a date, 1874. It’s not as old as the Croton Aqueduct manhole but it’s one of the few that still have the date on it. DPW stands for Department of Public Works
There’s even a whole book about NYC’s manhole covers for those with more interest in the aesthetics of the objects.