Xiàpī

Xiàpī was an ancient city on the plains east of Xúzhōu. At the end of the Hàn dynasty, Cáo Cāo diverted the Yí and Sì rivers against its walls, capturing the warlord Lǚ Bù after a siege. Centuries later, floods and sediment from the Yellow River buried the old city, whose walls lay beneath deep deposits.