Persepolis vs urban center

Persepolis and urban center both are nouns.

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

Persepolis (noun)	urban center (noun)
an ancient city that was the capital of the ancient Persian Empire; now in ruins	a large and densely populated urban area; may include several independent administrative districts