metropolis vs Sao Goncalo

metropolis and Sao Goncalo both are nouns.

Word	Noun	Adjective	Verb	Adverb
metropolis	Yes	No	No	No
Sao Goncalo	Yes	No	No	No

metropolis (noun)	Sao Goncalo (noun)
people living in a large densely populated municipality	an industrial city in southeastern Brazil across the bay from Rio de Janeiro
a large and densely populated urban area; may include several independent administrative districts