The former iron ore mine situated in the Bären valley at the foot of the Knöchel, east of Sankt Andreasberg forms the heart of the educational Roter Bär Pit today.

The mining of brown iron ore, which occurs here as lens-shaped inclusions in a Middle Devonian shale-limestone series, began around 1800 and ended in the mid-1860s.

Despite only moderate levels of iron content, this ore was in great demand because of its good smelting properties and high proportion of manganese.

With the transfer of Hanover to Prussia (in 1866) and the introduction of charcoal blast furnaces at the Königshütte smelter (in 1871) the ore from the Roter Bär no longer had a market.

Although the unworkability of the collapsed and practically exhausted deposit rapidly became clear, the search for as yet still undiscovered lodes of metal continued until 1923.

In 1931 the newly founded Sankt Andreasberg Society for History and Archaeology took the pit over and established the first visitor mine in the Harz.

The pit is not just used as a visitor mine, however; it is also to supply drinking water and, during the winter, acts as sheltered haven for bats.