These stand on Gorsty Knoll, near Coleford. They were the site where David Mushet set up an experimental furnace in 1818 and where his son Robert Mushet later operated his Forest Steelworks. There was also a brick works and a later, but short lived, blast furnace. Darkhill is the place where Robert Mushet perfected the Bessemer Process for making steel in bulk. Nearby are the scant remains of Robert Mushet’s Titanic Steelworks which produced the world’s first high speed tool steels. The site is a Scheduled Monument and owned by Forest Enterprise. The best view is from the disused railway formation.
In 2013, the Forest of Dean Buildings Preservation Trust carried out masonry conservation repairs here, funded by Forest of Dean Local Action Group.