Duddon Estuary

The Duddon Estuary is the sandy, gritty estuary of the River Duddon that lies between Morecambe Bay and the North Lonsdale coast.

The River Duddon and its estuary form part of the boundary of the historic county of Lancashire.

It opens into the Irish Sea to the north of the Furness peninsula; Walney Island forming part of its southern edge. Its 28 miles (45 km) of shoreline enclose an area of 13 square miles (35 km²), making it the second largest estuary in Cumbria after the Solway Firth and one of the six main estuaries in the historic county of Lancashire.

The main settlements alongside the Duddon estuary are Haverigg, Millom, Foxfield, Kirkby-in-Furness, Askam and Ireleth and Barrow-in-Furness.