The River Derwent starts at Styhead Tarn under Scafell Pike and flows all the way to the Irish Sea at Workington, through Derwent Water and Bassenthwaite Lake as it goes.
Around 30km from source to sea. Derwent derives from the old Celtic and literally means “River of Oaks” as huge swathes of its length are lined by oak trees. A popular canoeists trail is to follow the Derwent from Derwent water to Bassenthwaite Lake, then on to Cockermouth.
It’s also one of the principal game rivers in Cumbria and is known for salmon and some species of trout. Permits are required, follow link here for more information.