Hi, Claus, and thanks for posting this. Very, very good!
I agree with ravells about the paving stones, but I see them as part of a larger problem: random focus (sharpness) in some elements. For example, the paving tiles are in sharp focus, very crisp, whereas the stone path inside the walls is not. A few trees are sharp focused, but others aren't. Etc. If you are going for photorealism, either choose one level (ex: ground level) to be in sharp focus & slightly blur all others, OR blur or sharpen everything.
The shadows are also unrealistic if you are going for realism: where is the light source for this image? Even if directly above there should be shadows, etc. on the roofs.
Finally, the grunging of the map would add a lot. The grass, for example is too regular and "fill-like" for my tastes, as are the roofs, etc.
The grid on the stones outside the walls is also lost; how can you make it stand out? (Lighter color?)
Overall, this is a great image, one I would as a GM be proud to show my players, but if you do the above suggestions it would be eye-popping amazing!