With knee pads, waders and canoe - special tour underground

28 November 2019, Saxony-Anhalt, Sangerhausen: Thomas Wäsche (2nd from right), tour guide, explains to a group on an excursion through the Wettelrode reed shaft in the so-called "Green Vault" how the sintering on the gallery walls occurs. Since the shaft was abandoned in 1885, the permanently flowing water has dissolved minerals from the limestone, which forms a crust on the walls. The colour palette ranges from strong brown tones to white, green, turquoise, blue and black. For about 20 years the museum "ErlebnisZentrum Bergbau Röhrigschacht Wettelrode" has been offering longer excursions underground at a depth of about 300 metres. Recently, a new tour has been launched, where a part of the route is covered by canoes. The first miners began digging for copper ore in the Mansfelder Land about 800 years ago. From the year 1750 onwards, intensive mining was carried out. In total, approximately 2.6 million tonnes of copper and 14,213 tonnes of silver were extracted from the ore in the area. (to dpa "With knee pads, wader and canoe - special tour underground") Photo: Hendrik Schmidt/dpa-Zentralbild/dpa (Photo by Hendrik Schmidt/picture alliance via Getty Images)