One of the most famous genres of Anime is the infamous Isekai, which basically means a character gets sent to another world either by being reborn or being summoned or teleported. Doing this allows for the story to borrow from many different locations in order to get the vibe that they want for their story!
One thing that is very common in these types of anime is the sense of fantasy adventure which often derived from the medieval Europe are: Castles, Dungeons and villages while still taking inspiration from Japan.
While these two images are from the same anime (Reincarnated in another world with my smartphone) it shows the fact that they are in fact taking the inspiration from European architecture and Japanese Architecture from the medieval age.
Another example of this is the Anime: That time I was reincarnated as a slime.
This time however we see clear inspiration from Rome:
While one could say it is a bit of stretch, Please look at the image above and then to this next one:
Now I ain’t saying it’s directly inspired but it would be pretty hard to deny this! In fact once again while they take classical European buildings they also take from Medieval Japan:
When one thinks fantasy and magic one often thinks of the castles with dragons and Kings and Queens which is why when these Anime tackle the idea it is often depicted in the medieval European vibes.
Ultimately while we can use any sort of inspiration to showcase the idea of fantasy we often see it synonymous with the medieval European era as it is when we have the most tales such as the knights of the round table as well as Medieval Europe being known for their kings and queens with nobles and royal families in fact, England and Spain still have their royal families while not ruling anymore these countries still hold dear their ways.
With that being said, I have been Anthony!