Beginning in Stanhope the walk takes you across several burns and through a number of disused limestone quarries to reach the small hamlet of White Kirkley which sits above Frosterley. Limestone has been quarried from the valley sides around Frosterley since the 12th century but it was in the 1800s that the village became an important centre for limestone quarrying. Limestone has many uses - as a road stone, agricultural lime, for flux in the iron and steel industry and for cement. A special type of limestone is found in Frosterley; this fossil-rich stone, known as Frosterley marble, can be polished to a high shine. The most famous use of Frosterley marble is in Durham Cathedral. Here, the ceiling of the Chapel of the Nine Altars is supported by slender columns of this unusual stone.