With a total length of 110 kilometers, the Qinhuai River is the “Mother River” of Nanjing. When flowing into the city, it is divided into two tributaries at Nine-dragon Bridge outside Tongji City-Gate in the eastern suburbs of Nanjing. As the city moat, one is called the outer Qinhuai River circling the city-wall built in the Ming Dynasty. Termed as the inner Qinhuai River with a total length of nearly 5 kilometers and historically reputed as “Five-kilometer Qinhuai”, the other enters the city from Dongshuiguan Sluice and exits from Xishuiguan Sluice.