China Historical GIS, Harvard University and Fudan University CC BY-NC 4.0 https://maps.cga.harvard.edu/tgaz/placename/hvd_111529 潼關節度使 潼关节度使 Tongguan Jiedushi 防镇 防鎮 fang zhen defense command 784 4 792 4 POINT point N 34.51963 E 109.75989 唐 Tang CHGIS