Dunno if you still need this.
Many modern cities have a central plaza, where shopping, shows, games, etc happen in. They also have things similar to the Monk's Mound, like City Halls or buildings like that, and also neighborhoods around the city with families. Farms on the outside, though more far away, provide food as well in modern cities.
Umm, they were smart..?
I'm sorry I can't think right now I got like 5 hours of sleep my brain's fried