yes i researched there are maps for berserk, but Miura recently came out and said he just imagined berserk in Europe, like Chuder is France, and Midland is Denmark. However if you think about it this doesn't make sense with the context, and geography of the Manga. For example the siege of Doldrey takes place in a desert i don't know many deserts in Denmark. So any map i would find would probablly just show Europe or something, however if you know anything about the Japanese they are very spiritual poetry type people lol, they don't really care about location, in terms of where things are more of what the theme is, or the morals behind the place they are in. I believe Mirua doesn't really care where berserk takes place, more than he cares about the story, and the general medieval theme of the piece.
PS thanks for replying, and you really really need to read the manga ( its all free online, no download required) the Anime left so much out, and while is very good doesn't do the characters or story justice.