The Gambach plant is located in the Wetterau district in the German state of Hesse. The first signs of settlement indicate that there were already activities here in the Stone Age (2500–2000 BC). The Limes—i.e. the outer border of the Roman Empire between the Rhine and Danube—later ran to the west of this site. The Gambach silica sands formed much earlier in the Upper Oligocene and Miocene epochs are mined above and below the water table and subsequently processed. The high-grade raw materials of our Gambach plant are available as wet and dry sand. Some of the volumes are also processed into Croning sands for the foundry industry.