Pianguan

In 1958 and 1959 in conjunction with the execution of the Huanghe River (Yellow River) Water Conservancy Project, an investigation of paleolithic stone artifacts was conducted along the Huanghe River, from Togtoh County of the Nei Monggol (Inner Mongolian) Autonomous Region in the north to Pianguan County, Shanxi Province in the south, with Lamawan in Qingshuihe County as the center.