1. Saihanba National Forest ParkWeichang County Saihanba National Forest Park is a national forest park located in Weichang Manchu and Mongol Autonomous County, Chengde, Hebei, China, with Inner Mongolian Plateau standing in the northwest, covering an area of 200.29-square-kilometre . Established in 1962, this is a multifunctional botanical park integrating scientific research, plant species collection and display as well as tourism. Saihanba is often called the Green Lung of north China. From Wikipedia, the free encyclopedia.