53°36′47″N 2°59′28″W / 53.613°N 2.991°WThe West Lancashire Coastal Plain is a substantial area of land in the south west of Lancashire, England. It was formed after the Devensian glaciation, when glaciers retreated from the area around 12,000 years ago, leaving behind a flat, low-lying area of land between the Ribble and Mersey estuaries. The glaciers retreated, releasing glacial drift across the landscape, producing depressions and wetlands that gradually developed into the plain we see today.
The plain stretches from the Rimrose Valley in Seaforth, near Liverpool on the Mersey, to the south, to Preston on the Ribble, to the north. To the east, the plain is bounded by the foothills of the Pennines, while the western edge of the plain is separated from the sea by sand dunes. It is very flat, and much of it is only a few metres above sea level.