The North Pennines is the northernmost section of the Pennine range of hills which runs north–south through northern England. It lies between Carlisle to the west and Darlington to the east. It is bounded to the north by the Tyne Valley and to the south by the Stainmore Gap. Overview The North Pennines was designated as an Area of Outstanding Natural Beauty (AONB) in 1988 for its moorland scenery, the product of centuries of farming and lead-mining, and is also a UNESCO Global Geopark. At almost , it is the second largest of the 49 AONBs in the United Kingdom. The landscape of the North Pennines AONB is one of open heather moors between deep dales, upland rivers, hay meadows and stone-built villages, some of which contain the legacies of a mining and industrial past. The area has previously been mined and quarried for minerals such as barytes, coal fluorspar, iron, lead, witherite and zinc. Natural England maps Maps for North Pennines – Area of Outstanding Natural Beauty, showing Access, Designations and other criteria from Natural England: MAGiC MaP : North Pennines – AONB. MAGiC MaP : Hadrian's Wall – World Heritage Site. MAGiC MaP : North Pennines – Upland Breeding Bird Areas. MAGiC MaP : Pennine Way (Tan Hill – Dufton – Cross Fell). MAGiC MaP : North Pennines – SSSI (south). Geology The North Pennines are formed from a succession largely of sedimentary rocks laid down during the Palaeozoic era, later intruded by the Whin Sill and affected by glaciation during the Quaternary period. Mud and volcanic ash deposited during the Ordovician and Silurian periods were buried and subsequently faulted and folded during the Caledonian orogeny, the mudstone becoming slaty. These rocks which are between 500 and 420 million years old are now exposed along the great scarp which defines the western edge of the area and also in an inlier in upper Teesdale. Unseen at the surface but proved in boreholes is the Weardale Granite, a batholith emplaced as molten rock into the slates and other rocks around 400 million years ago. Its presence beneath the region results in it being an upland area since granite is relatively less dense and therefore ‘buoys up’ the North Pennines. This uplifted area is known as the Alston Block and is partly defined by major faults; the Stublick and Ninety-Fathom faults to the north and the Pennine Fault to the