The Longshan (or Lung-shan) culture, also sometimes referred to as the Black Pottery Culture, was a late Neolithic culture in the middle and lower Yellow River valley areas of northern China, dated from about 3000 to 1900 BC. The culture is named after the modern town of Longshan (lit. "Dragon Mountain") in the east of the area, under the administration of Zhangqiu City, Jinan City, Shandong Province. The first archaeological find (in 1928) and excavation (in 1930 and 1931) of this culture took place at the Chengziya Archaeological Site. The Longshan culture was noted for its highly polished black pottery (or egg-shell pottery). The population expanded dramatically, and many settlements had rammed earth walls. The population decreased in most areas around 2000 BC, until the central area developed into the Bronze Age Erlitou culture.