Maps of places that don’t exist are not a new idea. Whether or not maps are provided with a story, or whether fans map it out themselves, people like a sense of place provided with a story.
Here are a few examples I have found.
There haver been several iterations of Arkham and Innsmouth, by fans and through more official means, but the main things remain the same. Once you have provided a series of locations, and you know their vague relation to one another, you can start to map it out. As we know that Arkham and Innsmouth are in Massachusetts, we know that there will be a sort of grid pattern to the layout. If this were anywhere else, the layout would be slightly different. Knowing a vague location can change the interpretation greatly.
Middle Earth has had a map since its conception, to the best of my knowledge, but nevertheless, we know that it represents England and Ireland. People have made their own versions, but the major regions and the rough layout will be the same.
Neverwhere is quite an interesting one, because London exists. We know how London is laid out, we know how it works, but Neil Gaiman has used the template of London and reimagined it in his own way to produce a shadow version of London. We can follow the story on the map, however we know that because the London is not quite the same, it would not be the same experience. Using somewhere real as a template is an interesting technique, one used in the His Dark Materials Trilogy, and The Raw Shark Texts. Once again, we know the rough layout, but the world that is written about exists beneath what we can see, so there is still some room for artistic manipulation of space.
Twin Peaks is another interesting one, because we know roughly what it looks like. In the series, maps appear in various locations, and even reasonably detailed maps appear at one point in the Owl Cave, and on the blackboard in the Police Station, but this does not stop people from imagining it in their own way. Even given a very basic layout allows people to explore and imagine it in their own means.
Would it be best, then, to completely invent a new place, or to base Malice-Upon-Woe on a place that already exists? Could I borrow some locations from some places and make a hybrid of several towns? Should I be very detailed, or leave it more open to people’s imaginations? These are all things worth considering, and will change the way I create the maps.
For now, it is good to see the amount of detail that goes into other peoples ideas of what places look like.