Talsperre Schmalwasser, Reservoir dam in Tambach-Dietharz, Germany.

Talsperre Schmalwasser is a dam in the Thuringian Forest near Tambach-Dietharz that holds back a large reservoir surrounded by wooded hillsides. The structure is built as a rock-fill embankment and rises clearly above the surrounding valley floor, creating a wide open water surface.

Planning for the dam began during the final years of East Germany, driven by the need to secure the region's water supply. Construction continued after reunification and the facility gradually came into operation during the 1990s.

The reservoir draws families and walkers from across Thuringia who come to spend time along the water's edge and in the surrounding forest. The area around the shoreline offers spots to sit, watch the water, and enjoy the open air.

Several hiking paths run around the reservoir and vary in difficulty depending on the route chosen, so sturdy footwear is a good idea. Those arriving by car will find parking options near Tambach-Dietharz, which serves as a convenient starting point.

The dam's crest stands 76 metres above the valley floor, making it the highest dam in Germany by that measure. Its rock-fill body is sealed by an inner bitumen core, and a separate intake tower draws water, while a side overflow on the left slope handles flood discharge.