The River Derwent rises on Flyingdales Moor within the North York Moors National Park and from there it flows for 115 miles before reaching the River Ouse at Barmby on the Marsh.

The river marks the city's eastern boundary for some 10 miles running through the Parishes of Kexby, Elvington and Wheldrake. The area around Wheldrake is the start of the internationally important Lower Derwent National Nature Reserve. For more information visit www.english-nature.org.uk.