After much fiddling, I am fairly happy with this now. I have added blur to the road and a bit of edge fade to break the horrid texture up.
I think the towers are OK now I have changed the walls. I thought I would try the new borders from the November issue of the Cartographers Annual, it looks OK.
I have learnt a lot and the advice is certainly useful (keep it coming) and the different ideas make up for my lack of drawing skills!
I might call this one done, as my players need to go there tomorrow!