Mining of silver ore around Frohnau began in the 15th century. From the 18th century, the mining of bismuth, cobalt and nickel ores dominated. The Markus Röhling adit developed into one of the most important adits in the region. Located in the Sehma valley is the Frohnauer Hammer. This hammer mill, together with its technical equipment, is representative of the processing of different metals in the Erzgebirge. In 1907, it became the first technical monument to be protected in Germany.