necropolis vs burial site

necropolis and burial site both are nouns.

Word	Noun	Adjective	Verb	Adverb
necropolis	Yes	No	No	No
burial site	Yes	No	No	No

As nouns, necropolis and burial site are synonyms defined as:

Other synonyms of necropolis include burial ground, burying ground, cemetery, graveyard, memorial park.

necropolis (noun)	burial site (noun)
a tract of land used for burials	a tract of land used for burials