Over the course of time, Brilon's iron ore mining became of supra-regional importance and was one of Brilon's most important sources of income. The first furnaces for iron smelting were built on mountain slopes in order to use the upslope winds to Schüren the fire. As only low smelting temperatures could be achieved in this way and iron of inferior quality could be produced, the smelting furnaces were moved from the mountain slopes to the watercourses in the 14th/15th century. The water power was used to drive the bellows for the furnaces. When the more efficient coke-fired blast furnaces appeared in the Ruhrgebiet in the mid-19th century, the local ironworks were unable to withstand the competition and were abandoned.
"Heavy metal industry" in the Middle Ages
Slags were found in the Hilbringsetal valley, which were a waste product from the smelting of iron. The finds indicate that the iron ore extracted from the nearby Eisenberg was smelted here in the Middle Ages. The heavy iron transports have left deep hollows in the Brilon landscape.
