About 7000 years ago the area that now makes up the Beilun district was underwater with only the Tiantai mountains such as Taibai mountain and Lingfeng mountain visible. As the tides ebbed the land was gradually revealed and the peoples living in the area built ponds to block the tide and enclosed the sea area to set up land and improve the landscape. The regional landform of Beilun district is mainly characterized by hills and plains in the northwest and the middle, and hills in the southeast. It was separated by the Lingfeng mountain, thus, west of the mountain is the Changshan plain and east of the mountain is the Chaiqiao plain.