Wäsche IV is an ore crushing and concentration facility, located at the head of the Tiefenbach valley, some 250 m southeast of the rim of Altenberger Pinge. The technical monument is exceptional testimony to the technology of wet stamping: pounding as opposed to grinding, with the innovation of introducing water to the ore during crushing. This process was developed in the Ore Mountains in the 16th century, and became the principal method applied to profitably treat high-volume/low-grade tin ores of the Altenberg- Zinnwald Mining Landscape. The invention was rapidly adopted in the rich tin mining fields of Cornwall, UK, where it revolutionized ore recovery and output. The method subsequently diffused worldwide and could be applied to other ores.
The facility, in addition to its stamp mill, contains a complete system of ore concentration. Water was supplied by the 7.4 km long Aschergraben water ditch, constructed between 1452 and 1458, and which supplied numerous stamp mills in the Altenberg district. Following the end of operations in 1952, Wäsche IV was opened as a museum in 1957.
