The Polsterberg Pumphouse (German: Polsterberger Hubhaus) is a pumping station above the Dyke Ditch in the Upper Harz in central Germany which is used today as a forest restaurant. As part of the Upper Harz Water Regale it was built in the 18th century and was used to lift the water needed in Clausthal for the mining industry from the Dyke Ditch (Dammgraben) to the level of the highest pond, the Hirschler Pond. Aside from this water hoist, the Dyke Ditch supplied, and still supplies, water over ditches and tunnels to the Hausherzberg Ponds and the Lower Peacock Pond (Unterer Pfauenteich) (see also Middle Peacock Pond). The problem was however, that, as it happened, the most productive silver mines in the Upper Harz mining region, the Caroline Pit and the Dorothea Pit, were high up in the m