The Alte Tambacher Talsperre was built between 1902 and 1905 as the first drinking water reservoir in Thuringia to supply the town of Gotha with drinking water. It is also popularly known as the "Gothaer Talsperre" or "Stauweiher". The monumental structure in the Thuringian Forest was planned by Otto Intze, who was considered the most famous dam designer of his time. It took a total of 11 years to plan. The curved gravity dam made of porphyry quarry stones dams the water of the Apfelstädt and the middle water.

Between 1987 and 1991, the structure underwent a general inspection and reconstruction, during which the crown and base were provided with a concrete jacket that is up to 6.2 meters wide and provides additional stability. The dam was rebuilt in July 1991 after an official inspection.

Today's reservoir covers an area of approx. 11 hectares and has a water volume of 780,000 m³.

The dam is located in a hiking area. Hiking trails are excellent. A marked hiking trail (6 km) leads around the dam.

Today, this dam is no longer connected to the grid.