Introduction to Dalongtan: Dalongtan is located in the southeast of Jianwu City. It is unpredictable and deep, with a circumference of about 200 meters. In the early years, there was a temple next to it, but it later declined due to subsidence. There is ebony in the pool, which is large enough to cover the perimeter. Inscribed on the wall are the four characters "source of living water", which were inscribed by Li Dong, a guerrilla in Jianwu in the Ming Dynasty.