Euhemerism is a rationalizing method of interpretation that treats mythological accounts as a reflection of actual historical events shaped by retelling and traditional mores. In other words, religions are created as distortions of ancestors' tales over centuries or millenia, and euhemerism is an attempt to retrace the place of origin of the mythical lands.

I have done the work (pretty quickly, I admit) with Germanic paganism, and here is the map I have obtained based on my historico-geographic knowledge of Europe applied to the information on German mythology I found on Wikipedia. I have tried to place the nine worlds of Norse mythology :

For instance, the kingdom of Jötunheimr was located in the Swedish province of Värmland, according to Hversu Noregr byggðist

Hel and Niflheim being cold, unhospital places, they must have been in the top north of Scandinavia. The strange, short people that inhabit Hel must have been the Sami people of Lapland. As for the the shivering and shadowy spectres, how else could ancient people have better described the phenomenon of Aurora Borealis ?

As for Niðavellir, it is described as a mountainous land inhabited by dwarves (or dark-haired elves) and famed for its gold. I cannot help but see a link with the Nibelung dwarves, associated with the people of South-West Germany (Black Forest) and Switzerland, who according to the legend stole the Rhine Gold to make the ring of power.

I also added a few other place names :

- Hvergelmir : the wellspring of cold in Niflheim, source of the eleven rivers, Élivágar (probably in the mountains between Norway and Sweden, where many rivers have their source)
- Nörvasund, which is the Norse name of the Straits of Gibraltar.