urban center vs Cartagena

urban center and Cartagena both are nouns.

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

urban center (noun)	Cartagena (noun)
a large and densely populated urban area; may include several independent administrative districts	a port in southeastern Spain on the Mediterranean
	a port city in northwestern Colombia on the Caribbean