Most of the earliest cities around the world as excavated by archaeologists have evidence for the presence of social neighbourhoods.
The best neighborhoods have regulations controlling the built environment that enhance the neighborhood. By “built environment”, we mean its buildings (houses, apartments, stores, offices, public buildings like schools, even industries, and so on), streetscapes (including sidewalks, landscaped strips, sidewalks, on-street parking, traffic & bicycle lanes, etc.), and its parks and playgrounds.
