Near Boží Dar, the numerously well-preserved tips of waste rock bear testimony to the techniques of placer tin mining, performed here at least from the 16th until the 18th century. These heaps are evidence of the great extent to which placer mining was performed very high up in the Ore Mountains. The preserved area is over 250,000 m2 in size making the site one of the largest placer fields in Central Europe the significance of which is enhanced by its authentic state of preservation. The length of placers ranges usually between 5 to 10 m, but can reach 20 m or more, and the height of the mounds is even beyond two metres. Placers are concentrated primarily in the area to the west of Boží Dar, along the left tributary of Černá stream where the length of the placers reaches about 1 km, along the watercourse of Černá itself (about 800 m) and along an unnamed stream on the eastern edge of the Božídarské rašeliniště National Nature Reserve (about 400 m). In addition, numerous placers are also situated lower, downstream of Černá stream.
During placer mining, the lightest components of alluvium deposits along with the humus substrate were removed, hence the placer mounds are poor in nutrients. Therefore, the vegetation that grows on them markedly differs from that growing in the surrounding landscape. The heaps, with their typical vegetation such as heather, cranberries, mountain everlasting, festuca rubra, or arnica constitute a wholly unique and formative element of the landscape in the area around Boží Dar.