While there will always be more to be said, the diverse opinions on this issues found in: Did the ancient Norse believe that the other realms (Asgard, Jotunnheim, etc.) were other planets like in the Marvel movies, other "planes" like in D&D, physical places that you could get to by conventional means (albeit with difficulty) or something else entirely? might be interesting to OP.

What I (repeatedly) pointed out in the linked thread is that the at least many current place names in Scandinavia, apparently related to Old Norse mythology and supernatural beings, often don't have ascertained medieval or further older provenance.