Adit of the former uranium mine Poehla, Erzgebirge, Germany: the adit is nearly 8 km long and connected to the Sn-Zn-Fe exploration area Haemmerlein (at about 3 km, exploration only, today visitor mine) and the U-Fe mining area Tellerhaeuser at 7 km. Construction of the adit began in 1967, uranium production started in 1983 and ended in 1991.
<a href="//commons.wikimedia.org/w/index.php?title=User:Geomartin&amp;action=edit&amp;redlink=1" class="new" title="User:Geomartin (page does not exist)">Geomartin</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>