nether region vs mythical place

nether region and mythical place both are nouns.

Word	Noun	Adjective	Verb	Adverb
nether region	Yes	No	No	No
mythical place	Yes	No	No	No

As nouns, mythical place is a hypernym of nether region; that is, mythical place is a word with a broader meaning than nether region:

nether region: (Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment
mythical place: a place that exists only in imagination; a place said to exist in fictional or religious writings

Other hypernyms of nether region include fictitious place, imaginary place.

nether region (noun)	mythical place (noun)
(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment	a place that exists only in imagination; a place said to exist in fictional or religious writings