Furness (FUR-nəs) is an area of Cumbria in northwestern England. Together with Cartmel it forms North Lonsdale, which was historically an exclave of Lancashire. The region may be split into two areas: Low Furness and High Furness. The former consists of the headland bounded on west by the Duddon estuary and on the east by Morecambe Bay, while the latter extends inland into the Lake District and contains the Furness Fells. Off the southern tip of Low Furness is Walney Island, eighteen kilometers in length, as well as several smaller islands.