Since the 1980s, Karmansbo ironworks has been one of the many sites of the huge Ekomuseum Bergslagen. It is a forge preserved in working order for converting pig iron into wrought iron, which was used to make high-quality tools. An ironworks existed on the site in the seventeenth century. It was redeveloped in the 1870s and operated until 1958. Although damaged by floods in 1977, since 1982 it has been owned by the local council and restored. Karmansbo used the ‘Lancashire forge’ method developed in Sweden of refining iron with charcoal fuel. The pig iron was re-smelted then heated and hammered to reduce the carbon content and rolled into bars.
The blowing equipment, hammers and rolling mills are powered by a turbine and a waterwheel. The main forge building next to the river contains the furnaces and reheating forges, hammers and rolls. At certain times, demonstrators show charcoal burning, operate the furnaces and pass red-hot iron through the rolling mills. Visitors also see the houses of the workers, one of which is furnished and the 1759 mansion of the forge master, which is now a hotel.