The present-day Stahlwerk Thüringen GmbH plant at Unterwellenborn, east of Saalfeld in Thuringia, succeeds the Maxhütte, a blast furnace complex established in 1872 as a branch of the Maximilianshütte in Sulzbach-Rosenberg in northern Bavaria. The blast furnaces continued to operate until 1992, and the present plant, based on electric arc furnaces, dates from 1995. The principal monument remaining from the former ironworks is a lofty, steel-framed brick hall built in the 1920s to accommodate seven large gas engines, which operated the furnace blowing machines, using as their fuel the waste gases from the furnaces. One of the engines is preserved, and a Bessemer converter is displayed outside the building. There are displays in the gas machine hall illustrating the history of the Maxhütte and a voluntary association organises a lively programme of cultural events.