Lower Harz Pond and Ditch System
Within the Lower Harz region (in the counties of Harz and Mansfeld-Südharz in central Germany) are still many traces of the historical water management facilities used by the mining industry. In addition to water-carrying ditches and ponds, there are also long-abandoned ditches and dry pond beds.
Source: Wikipedia — Lower Harz Pond and Ditch System (CC BY-SA 4.0)