The buildings are mostly O Scale Railroad buildings - most of them Ameritowne. I laid out the buildings on 4 2' by 4' sections.
I built the sections out of 1"x2" furring strips that were backed with pegboard to add structure. I stretched canvas dropcloth over the sections and painted them- making sure that the roads were wide enough for a good game. The little park scene was put in mainly because I did not have enough buildings. At one end I build an area with port and warehouses.