Helen Furnace
Highland Township, PA
In the wooded hills of Clarion County, the stone stack of the Helen Furnace still stands as a relic of Pennsylvania's antebellum iron boom. Built in 1845, this was a cold-blast charcoal furnace—an early industrial technology that smelted local iron ore using heat drawn from surrounding hardwood forests. It was one of dozens of such furnaces that dotted the county between roughly 1829 and 1867, when the region earned the nickname "The Iron County" for the sheer density of its ironworks.