This tajch (a historic mining reservoir) lies at an altitude of 630 m.
It was built in 1740–1743 to serve the Moderštôlňa mines and fulfilled its original purpose until mining there came to an end in the second half of the 19th century. Later it was used for recreation and fish farming.
In 1997 a full overhaul of the dam and outlet system was completed, restoring the reservoir to its original appearance. Besides gold and silver ores, iron ore was mined around Kopanice for many years, and lime was burned here too.
