Along the Harlem River Speedway
The Harlem River Drive of today started as the Harlem River Speedway, a well maintained flat track that was favored by 'the racing sets' at the turn of the 20th century. The New York City Department of Public Parks at that time was responsible for not only parks but roads, bridges and sometimes sewers and waterworks for a large swath of upper Manhattan and the annexed Bronx districts. This cover, with its elaborate monogram is a memento, that can be fairly closely dated. Construction on the Speedway began in 1894 (it opened in 1898) the same year that the DPP was dissolved succeeded by the NYC Department of Parks.
The rings of stubs was a well established design by 1894, although mostly for smaller coalhole covers. The central monogram, here a rather extravagant DPP, was becoming a city-wide craze in manhole cover designs in all five boroughs.
Sewer Cover. The DPP covers along the Harlem River Drive are all aligned with other covers typically seen over sewer lines and track the drainage system of the Speedway.
This cover was seen on the Harlem River Driveway approach to the Drive from 155th St. There are at least 3 more identical covers along the drive. Similar covers are seen scattered about the city, but I have not seen anymore with DPP.