《水经注·卷二十九》
丹徒县城北二百步有一座旧城，本来是毗陵郡的治所，过去距江岸约三里，江岸逐渐崩塌，江流就移到城下了。
丹徒县北二百步有故城，本毗陵郡治也。旧去江三里，岸稍毁，遂至城下。
There is an old city two hundred steps north of Dantu County, which was originally the seat of Piling County. In the past, it was about three miles away from the river bank, but the river bank gradually collapsed, and the river moved under the city.