The Forest of Dean had an iron industry from the Iron Age to the late 1800s. The limonite ores occur within a narrow band of the Carboniferous Limestone known as the Crease Limestone.
Iron ore mining and smelting were probably continous throughout the two and half millenia. There were major peaks in production in the Romano-British times, during the middle to late Middle Ages, with the charcoal blast furnace from 1600 to 1800 and the coke blast furnace from 1800 to around 1870.
The dip of the Crease Limestone is around 10 degrees at Puzzle Wood giving rise to the broad outcrop which contained numerous ore bodies. Direct dating is wanting but the likely age of extraction is from Romano-British to Medieval. Romano-British settlement sites (AD 100-400) are known 0.7km north with Romano-British smelting at Coleford and 0.6km southwest.