Sakura Park, Morningside Heights
Sakura Park was created in 1896 across Riverside Drive from Grant's Tomb. The park was substantially redesigned in 1932, and this drain cover (and at least 3 more) may have been installed then.
The design is a standard Campbell item (catalog #1049) with the Cambell blaze often replace with nothing or with the appropriate department and location names.
The placement of the covers in the large central lawn of the park, and the eight drainage holes indicates this is most likely a sewer cover.
This design is found throughout New York City. see number 249 in Fort Tildon in the Rockaways, for a near duplicate.