This was the case for both brand new cities built from scratch and also when walled cities were built around preexisting population concentrations. In Chang'an, several neighborhoods were sparsely populated, indicating that the authorities had left room for unanticipated growth. It was discovered in 1945 when aerial mapping was done of Quanzhou in Fujian that one-fourth of that city was still open space.
唐朝長安城，西南面幾個格子狀的坊裡居住人口都很少，顯示還有不少可發展的空間；福建泉州城，在一九四五年經航空測繪訂正的地圖上，也仍有四分之一是空地；作家胡耐安曾說，南京城的佳勝處，便是在市廛塵擾裡饒有鄉村景物。