The Langdale axe industry is the name given by archaeologists to specialised stone tool manufacturing centred at Great Langdale in England's Lake District during the Neolithic period (beginning about 4000 BC in Britain). The existence of a production site was originally suggested by chance discoveries in the 1930s, which were followed by more systematic searching in the 1940s and 1950s by Clare Fell and others. The finds were mainly reject axes, rough-outs and blades created by knapping large lumps of the rock found in the scree or perhaps by simple quarrying or opencast mining. Hammerstones have also been found in the scree and other lithic debitage from the industry such as blades and flakes.