In the course of time, iron ore mining in Brilon gained supraregional importance and represented one of the most important sources of income for Brilon. The first furnaces for iron smelting were built on mountain slopes in order to use the slope winds to Schüren the fire. Since only low melting 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 could not withstand the competition and were abandoned.
"Heavy metal industry" in the Middle Ages
In the Hilbringsetal valley, slag was found that was a waste product from the smelting of iron. The findings indicate that iron ore mined in the nearby Eisenberg was smelted here in the Middle Ages. The heavy iron transports have left deep hollow ways in the Brilon landscape.