OS Grid Reference: SO589088In 1818 David Mushet, of Coleford, built a cupola for metallurgical experimentation at Darkhill., where a year or two later Moses Teague found a way to 1818 David Mushet, of Coleford, built a cupola for metallurgical experimentation at Darkhill., where a year or two later Moses Teague found a way to make good iron with the coke of local coal. The location of the ironworks, set as it is some distance from the local villages, was reputedly picked to avoid rival iron makers from discovering Mushets methods. During the next 20 years David Mushet perfected the making of superior quality refined iron that was more malleable and suitable for tinplate making. At Dark Hill David Mushet built a second furnace before 1845, when he handed over the works to his sons William, David and Robert. Robert Mushet became manager in 1845 and later developed self hardening steel. The ironworks were sold before 1874 to the Severn & Wye Railway who constructed an embankment across the east end of the site to carry the Coleford Railway. The visible remains which can be seen from the adjacent public footpath, which follows the line of the abandoned railway, include the site of brickmaking drying sheds, kilns, smiths shop, charging incline, blast furnace and blowing engine house. In 1999 the FODLHS together with Forest Enterprise placed a monument at Darkhill commemorating the achievements of the Mushets at the site.