As the exclusive three Antique Shell Dikes in the world, the only one in China is in Huanghua city of Cangzhou, whose forming and abundant ancient ocean cultural relics has drawn much attention from scholars home and abroad. In September of 1988 the provincial natural preservation of Antique Shell Dike in Huanghua city was founded.
It is said that Antique Shell Dike in Zhaojiabao of Nanpaihe Town in Huanghua City consists of living things like shells,
There are 6 Antique Shell Dikes in Huanghua city, distributed nearly paralleled with modern coastal lines, with a longitude of about 31square kilometers, which took shape respectively from about 6000 or 7000 years ago to about 1000 years ago. According to the evidence from the scientists, these antique shell dikes are natural sea shield formed by weathering myriads of shells and its scraps carried by waves when tides rise and fall in the Bo Sea in the long term.
Being the most intact one in the world so far, the Antique Shell Dike in Huanghua city has been an important outcome in the process of eastern coast of Bo Sea’s taking into land shape since 7000 years ago, whose developmental scale, lasting time and the contained geographical information of ancient environment are rare throughout the world and playing an important role in the 4th international geographical research. It can provide natural script for the research of ancient ocean transformation and environment change trend, of important scientific value for predicting future environment change trend. Moreover, its formation and abundant ancient ocean cultural relics have drawn attention of scholars home and abroad since the 1920s.
The 5 antique shell dikes on the land are buried deeply underground except the 2nd one naked on the surface. The 2nd antique shell dike, used to be a precious natural sea shield with a total length of 60 kilometers or so stretching from Tianjin in the north to Haixing in the south, is about 2 to 3 meters high with a breadth of about 1500 meters from the east to west, covered by wild jujube trees and rich in many rare medicinal materials such as Shaseng, Chinese ephedrine, jujube seeds, Tuyuan, etc. Because of luxuriant plants, it is also a paradise for the fox, badger and wild rabbits. The soil on the antique shell dike is soft, good for storing rainwater so that if a hole is dug on antique shell dike the sweet water will leak endlessly. The antique shell dike not only prevents the tide for the village but also is the natural navigation aids for the fishermen, when they see the green dike in a far distance on the sea just like they see their cozy home.