urban center vs Matamoros

urban center and Matamoros both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban center	Yes	No	No	No
Matamoros	Yes	No	No	No

urban center (noun)	Matamoros (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in northeastern Mexico opposite Brownsville near the mouth of the Rio Grande