I
7，000 years ago，the area where Shanghai now sits was under the sea.As the years passed，the Yangtze and other rivers brought sediment which formed a coastal plain.Early people later settled down on this part of the land and Shanghai was brought into the course of history.Some 6，000 years ago the indigenous Majiabang culture began to evolve，followed by the Songze culture 5，000 years ago，the Neolithic Liangzhu culture 4，000 years ago，and the Maqiao culture 3，700 years ago，which thrived until the 29th year of the Yuan Dynasty（A.D.1291）when Shanghai was formally established as a county.This paved the way for Shanghai's cultural fountainhead and clearly marked its roots in civilization.