The Yancheng City, located in Wujing District of Changzhou Municipal City, is an ancient relic from the Western Zhou Dynasty of the Spring and Autumn Period, the only perfectly survived one of its kinds in China. It has been nearly 3,000 years of history. Its water town system consists of three protective walls surrounded by the three protective rivers and its virgin ecological forest constitutes a wonder in the world. It is on the list of the Key Cultural Relics of China.