Mainland Chinese experts on traditional Chinese cities note that before the Yuan court established its capital Beijing, its builders first laid underground sewers that followed the lay of its land.
研究中國傳統城市的大陸學者指出，元朝興建大都（北京）之前，首先在地下順著地形的坡度，鋪設下水道，裝置了排水措施，其次才在地面上根據分區佈局原則，進行設計。