administrative county in the northwest of England. It comprises six districts: Allerdale, Eden, and South Lakeland, the boroughs of Barrow-in-Furness and Copeland, and the city of Carlisle. The administrative county comprises the historic counties of Cumberland and Westmorland and parts of the historic counties of Lancashire and Yorkshire.

The county extends along the Irish Sea coast from Morecambe Bay to Solway Firth. It includes the famous scenic Lake District, where a deeply dissected dome of ancient volcanic and slate rocks forms a landscape of mountain peaks (the Cumbrian Mountains) and lake-filled valleys. Newer outcrops of limestone and sandstone form the surrounding lowlands of the Carlisle plain and the valleys of the Rivers Eden and Kent. In the extreme east several high hills (including Cross Fell and Knock Fell) form part of the Pennines, the “spine” of England.

The main agricultural activities in this largely rural county are sheep farming on the rough uplands and crop production in the more fertile lowlands. The Rivers Eden, Derwent, and Esk are noted for salmon fishing.

There is a large naval shipyard in Barrow-in-Furness and light industry in Workington and Whitehaven, and Britain's chief nuclear fuel reprocessing and recycling centre is at Sellafield on the Irish Sea coast. The main western railway and the principal motorway to Scotland pass through Penrith and Carlisle, and Carlisle serves as a transport, distribution, and communications centre. Tourism also plays a crucial role in the county's economy.

The principal population centres are Carlisle, Penrith, Kendal, and the ports of Barrow-in-Furness, Whitehaven, and Workington. Carlisle, the county's largest town, is the administrative centre. Area 2,613 square miles (6,768 square km). Pop. (2005 est.) 498,900.