Santiago de los Caballeros vs metropolis

Santiago de los Caballeros and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
Santiago de los Caballeros	Yes	No	No	No
metropolis	Yes	No	No	No

Santiago de los Caballeros (noun)	metropolis (noun)
city in the northern Dominican Republic	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts