I am looking to create a city for my campaign that is extremely ordered in terms of its construction. The basic idea that I want is that the main city streets form a large magic/summoning circle that is hidden in plain sight. The problem I am having is creating this city and hiding the thing. Any attemps I have made have resulted quite poorly and the shape of the circle is obvious. So I am wondering how I can hide this thing from my players by integrating side streets etc to hide the shape. Don't have any images at the moment as I am not currently at my PC. Any ideas?