The Aschergraben is one of the most important technical achievements from the early period of mining in Altenberg. It is the oldest artificial water complex in the Altenberg mining district. The artificial water course was constructed between 1452 and 1458. For over 500 years, it reliably provided water to the water wheels and ore dressing works. The Aschergraben carried the water from the border forests above Cínovec to Altenberg over a distance of 7.4 kilometres along a downward incline of 0.3-0.6%. After mining in the area ceased, the water from the ditch was no longer needed. Nevertheless, the Aschergraben has been retained as a viable water course.