fairyland vs mythical place

fairyland and mythical place both are nouns.

Word	Noun	Adjective	Verb	Adverb
fairyland	Yes	No	No	No
mythical place	Yes	No	No	No

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

fairyland: the enchanted realm of fairies
mythical place: a place that exists only in imagination; a place said to exist in fictional or religious writings

Other hypernyms of fairyland include fictitious place, imaginary place.

fairyland (noun)	mythical place (noun)
something existing solely in the imagination (but often mistaken for reality)	a place that exists only in imagination; a place said to exist in fictional or religious writings
the enchanted realm of fairies