Cwm-y-glo means in Welsh, "valley of coal" -- not coal in the sedimentary-rock sense, but charcoal; with an important sub-industry of the local slate quarrying, having been charcoal burning: to fuel the foundries at the various quarries, making iron artefacts for quarry use. Charcoal-burning was likewise for long, an important activity in the Weald of Sussex. The Weald and Downland Living Museum at Singleton, West Sussex: has among many other features, a reconstruction of a charcoal-burners' camp.