MERSEY is a river in western England. It originates in Stockport (Greater Manchester) in the Pennine Hills, where it is formed by the confluence of three tributaries: the Etherow, the Goyt, and the Tame. The Mersey flows into the Irish Sea through the Liverpool Bay, creating an estuary.
The river is navigable and runs parallel to the Manchester Ship Canal. It is also connected to the River Trent via a canal. Cities along the Mersey include Manchester and Liverpool. For centuries, the river served as the boundary between the historic counties of Lancashire and Cheshire.