Harley Street vs Greater London

Harley Street and Greater London both are nouns.

Word	Noun	Adjective	Verb	Adverb
Harley Street	Yes	No	No	No
Greater London	Yes	No	No	No

Harley Street (noun)	Greater London (noun)
a street in central London where the consulting rooms of many physicians and surgeons are located	the capital and largest city of England; located on the Thames in southeastern England; financial and industrial and cultural center