Jupiter Mine Tunnel (1783)

The Jupiter colliery in Witten (Bommerholz-Muttental district) is a former hard coal mine. The colliery was also known under the names Zeche Jupiterbank, Zeche Jupiter Bank, Zeche Juppiter and Zeche Jupiter I & II. The colliery was located in the area of Rauendahlstraße east of Bockampstraße. In the second half of the 19th century, the mine belonged to the Märkisches Bergamts district and there to the Hardenstein jury area.

de.wikipedia.org/wiki/Zeche_Jupiter

"...In addition, we keep discovering tunnel entrances along the entire hiking route, some of which are quite small and well hidden. There is an information board for each of these collieries with explanations about the tedious work back then...."
You can find more information at: netreisetagebuch.de/bergbauwanderweg-muttental

Super nice the area here