Boston Navy Yard vs Charlestown Navy Yard

Boston Navy Yard and Charlestown Navy Yard both are nouns.

Word	Noun	Adjective	Verb	Adverb
Boston Navy Yard	Yes	No	No	No
Charlestown Navy Yard	Yes	No	No	No

As nouns, Boston Navy Yard and Charlestown Navy Yard are synonyms defined as:

Boston Navy Yard and Charlestown Navy Yard: the navy yard in Boston where the frigate `Constitution' is anchored

Boston Navy Yard (noun)	Charlestown Navy Yard (noun)
the navy yard in Boston where the frigate `Constitution' is anchored	the navy yard in Boston where the frigate `Constitution' is anchored