I appriciate the replies and all the assistance! Thank-you all. I was thinking of making the 6 outter points a guard towers and perhaps a wall around the whole thing. I like the idea of adding a building at each circle and as for the centre, I was going drop a castle there. My original plan for this was to be a completely square city and somehow fit this in without drawing attention to it. Angled lines would really appear in a perfectly square backdrop... so thats a no go. I will play around with the idea of mixing up walls and walkways as part of it as well. I will certainly expland the city out beyond the confines of the circle to further throw things off and misdirect people. I am not sure an Iso map would accomplish what I want, and my players are used to getting a full topdown view of the city (As per all my previous games). Changing that up may be nice for them, though they may suspect something. In addition to that, I am not sure I have the time or skill to do one up I will re-work it again and see what I can come up with. Of course all of your suggestion will be quite handy in helping me improve and refine this.
Thanks

Hopefully I will be able to post again soon, have a rather busy day ahead of me.