open ▁as ▁a ▁test ▁mine ▁for ▁col li ery ▁machines . ▁It ▁ 1 9 8 7 ▁the ▁site ▁was ▁given ▁listed ▁status . ▁Short ly ▁before , ▁in ▁ 1 9 8 2 , ▁an ▁open - air ▁museum ▁had ▁been ▁set ▁up ▁on ▁the ▁surface ▁site : ▁that ▁closed ▁in ▁ 1 9 9 6 . ▁The ▁current ▁visitor ▁mine ▁museum ▁opened ▁to ▁ 1 7 0 m ▁in ▁ 2 0 0 7 ▁and ▁to ▁the ▁full ▁ 3 2 0 m ▁in ▁ 2 0 0 8 . ▁ ▁Techn ically ▁the ▁early ▁mine ▁had ▁to ▁cont end ▁with ▁sand ▁and ▁the ▁Sa ara ▁t ect onic ▁fault . ▁The ▁first ▁sh aft , ▁the ▁ 1 8 5 6 ▁Barbara ▁sh aft ▁was ▁abandoned ▁at ▁ 3 0 m . ▁The ▁second ▁sh aft , ▁the ▁Con cord ia ▁sh aft ▁was ▁renamed ▁the ▁Gu ido ▁sh aft . ▁Ex pl or atory ▁min ing ▁at ▁ 8 0 m ▁was ▁abandoned ▁due ▁to ▁fault ing . ▁At ▁ 1 1 7 m ▁water ▁was ▁struck . ▁Fin an cial ▁assistance ▁was ▁received ▁from ▁the ▁Upper ▁S iles ian ▁Railway ▁Association ▁. ▁Gu ido ▁was ▁dra ined , ▁and ▁a ▁new ▁sh aft , ▁the ▁Railway ▁sh aft ▁was ▁d ug - ▁the ▁ 1 7 0 m ▁level ▁was ▁explo ited ▁using ▁short wall ▁exc av ation . ▁The ▁work ings ▁were ▁bought ▁in ▁ 1 8 8 7 ▁by ▁the ▁Pr uss ian ▁Fin anz amt