China Historical GIS, Harvard University and Fudan University CC BY-NC 4.0 https://maps.cga.harvard.edu/tgaz/placename/hvd_111559 沂海觀察使 沂海观察使 Yihai Guanchashi 防镇 防鎮 fang zhen defense command 819 4 820 4 POINT point N 35.07156 E 118.34095 唐 Tang CHGIS