Harlem River vs New York City

Harlem River and New York City both are nouns.

Word	Noun	Adjective	Verb	Adverb
Harlem River	Yes	No	No	No
New York City	Yes	No	No	No

Harlem River (noun)	New York City (noun)
a channel separating Manhattan from the Bronx	the largest city in New York State and in the United States; located in southeastern New York at the mouth of the Hudson river; a major financial and cultural center