region vs promised land

region and promised land both are nouns.

Word	Noun	Adjective	Verb	Adverb
region	Yes	No	No	No
promised land	Yes	No	No	No

As nouns, promised land is a hyponym of region; that is, promised land is a word with a more specific, narrower meaning than region:

region (noun)	promised land (noun)
a part of an animal that has a special function or is supplied by a given artery or nerve	any place of complete bliss and delight and peace
a knowledge domain that you are interested in or are communicating about
the extended spatial location of something
a large indefinite location on the surface of the Earth
the approximate amount of something (usually used prepositionally as in `in the region of')