urban center vs Oaxaca City

urban center and Oaxaca City both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban center	Yes	No	No	No
Oaxaca City	Yes	No	No	No

urban center (noun)	Oaxaca City (noun)
a large and densely populated urban area; may include several independent administrative districts	a city of southeastern Mexico