Set in the Duddon Valley along the Corney Fell Road, this charcoal-fired iron furnace, built in 1736, is is the oldest surviving site of its kind in northern England. A huge wheel, turned by water from the river, drove the bellows that pumped air into the blast furnace. Recent conservation work has helped save the original buildings, which include the towering furnace stack and storerooms for iron ore and charcoal. It is managed by the Lake District National Park Authority and free to visit.