The Northumbria RBD, which covers an area of 9,029 sq km, includes Northumberland and County Durham, with small areas of North Yorkshire and Cumbria. Northumbria's landscape is one of extreme variation, from highly industrial urban areas to moors, hills and valleys of the National Park, the Heritage coastline and the Pennines AONB. Approximately 2.5 million people live in the region, primarily in two locations: Tyne and Wear, and the Tees Valley. The most significant cities and towns include Sunderland, Newcastle, Durham, Stockton and Middlesbrough. To the west, a diverse rural landscape supports a range of agricultural activities from livestock and dairy farming to cereal and vegetable production. Forestry is also a significant industry.