Two things to add here:

First, this fortress is based on Mjälleborgen, a real hillfort on Frösön. This is a bit of an anachronism in a way, since the real fortress was from the iron age and was burnt down around 400 years before this takes place, but i figured that since i was gonna have a fortress in the story anyway, then i might as well use one that actually existed.

Second: The fortress is kind of a pain to draw so drawing this was quite cathartic!