Gougnies offers the remains of the birth of the steel industry. The subsoil, rich in iron ore, has been mined from the earliest times and with certainty in the 3rd century. Documents attest to this activity in the 16th century. In the castle, there are well-preserved forge buildings and a furnace crucible. In 1605, forges, furnaces and platinerie were mentioned in the donation to François de Sire. At the beginning of the 19th century, the furnace and the refinery were in the hands of the Puissant family. In the middle of the 19th century, the furnace became the property of the Gougnies company, which built a coke blast furnace with an iron factory and a rolling mill attached.