The areas of Millstone Grit form an 'inverted horseshoe' around the lower uncapped limestone areas of the White Peak, enclosing it to the west, north and east. Hence the Dark Peak is said to cover the higher, northern moors between the Hope Valley and South Pennines, the Western Moors stretching south to near the Churnet Valley, and the Eastern Moors southwards towards Matlock. The Dark Peak is one of 159 National Character Areas defined by Natural England; as defined by Natural England, the Dark Peak NCA covers and includes the northern block of hills approximately bounded by Marsden, Stocksbridge, Hathersage and Chapel-en-le-Frith, plus the eastern moors between Hathersage and Matlock, but excludes the western moors between Chapel and the Churnet Valley (which it places in NCA 53, the South West Peak), and the area around Glossop (in NCA 54, Manchester Pennine Fringe).