The River Caldew is a notable tributary of the River Eden, draining the Skiddaw fells of the Lake District and flowing northward through Cumbria before joining the Eden at Carlisle. Fed by the high fells, the Caldew is a classic freestone river exhibiting characteristics typical of upland Cumbrian streams — fast-flowing riffles, gravel and shingle beds, and productive pools that hold both salmonids and coarse fish. The river passes through varied terrain, from the open moorland of its upper reaches near Mosedale and Caldbeck to more pastoral lowland stretches as it approaches Carlisle. The Caldew is managed as part of the broader Eden catchment and is an important river for Atlantic salmon, brown trout, sea trout, and grayling, with ongoing conservation work supporting fish populations throughout the system.