Introduction to the Middle and Upper Proterozoic: The National Nature Reserve of the Middle and Upper Proterozoic stratigraphic profile is referred to as "Jixian Profile" and was established in October 1984. The nature reserve ranges from Changzhou Village at the foot of the Great Wall in the north to Fujun Mountain in the north of ancient Yuyang City in the south. The main protection object is a well-preserved ancient stratum with simple structure and continuous exposure, which is known as a rare and valuable geological treasure. , can be called the world's precious natural historical heritage. In addition, the reserve is connected to the Baxian Mountain National Nature Reserve to the east, Panshan National Natural Scenic Area to the west, Wuling Mountain National Nature Reserve in Xinglong County, Hebei Province to the north, and to the south is an unobstructed view of the North China Great Plains, a famous historical and cultural city - You can have a panoramic view of the ancient Yuyang and the rippling green Cuiping Lake. It is a good place to climb up and have a good view.