The Upper Harz Water Management System is also called "Water Regale". It is the third component of the Cultural Heritage Site which has existed since 1992, encompassing the Rammelsberg mine and the Old Town of Goslar.
In St. Andreasberg, you can experience a still-active energy system: Visit the Samson Mine, the Oderteich reservoir (a UNESCO World Heritage Site), and discover another highlight of the Upper Harz water management system on a hike along the Rehberger Graben canal. Stop along the way at the historic Rehberger Grabenhaus, now a popular restaurant with a wildlife feeding station.
This system of ponds, ditches, mines and adits forms the world’s largest energy system from pre-industrial times. Water was used to load water wheels, drive pumps, move ore bins and transport miners. Today, you can experience this Cultural Heritage Site both above and below ground on various tours and walks.
More information is available here.