The Grüner Graben water ditch, which still carries water today and is largely preserved in its original condition, is one of the most important witnesses for silver and tin mining in the area around Pobershau. It is a prime example for the water management systems in the Marienberg mining area. Built in the 17th century, the eight-kilometre-long, man-made ditch supplied water for the mines, ore stamp mills and ore washers. From the 19th century, it was used to supply water to the region’s emerging industry.