a ' s ▁name ▁der ives ▁from ▁the ▁word ▁for ▁ore ▁in ▁Spanish ▁language , ▁for ▁it ▁has ▁rich ▁iron ▁ore ▁depos its ▁that ▁were ▁explo ited ▁since ▁ancient ▁Cel ti ber ian , ▁and ▁later ▁also ▁during ▁Roman ▁times , ▁well ▁until ▁the ▁late ▁ 2 0 th ▁century . ▁ ▁A ▁ 2 0 0   km ▁long ▁railway ▁line ▁was ▁built ▁by ▁the ▁Com pa ñ ía ▁Min era ▁de ▁Sierra ▁M ener a ▁S . ▁A . ▁in ▁ 1 9 0 3 ▁in ▁order ▁to ▁bring ▁the ▁iron ▁ore ▁to ▁the ▁har bor ▁of ▁S ag unto . ▁This ▁was ▁the ▁longest ▁private ▁company - owned ▁railway ▁line ▁in ▁Europe . ▁A ▁bl ast ▁furn ace ▁facility ▁also ▁belonging ▁to ▁the ▁company ▁was ▁also ▁located ▁in ▁S ag unto , ▁where ▁a ▁pel let izing ▁plant ▁and ▁a ▁long ▁jet ty ▁were ▁built ▁in ▁the ▁ 1 9 7 0 s . ▁ ▁The ▁Sierra ▁M ener a ▁range ▁has ▁been ▁much ▁scar red ▁by ▁environment ally ▁uns ound ▁min ing ▁practices ▁across ▁the ▁centuries . ▁There ▁are ▁many ▁tons ▁of ▁un tre ated ▁de br is ▁and ▁sl ag ▁scattered ▁across ▁the ▁range , ▁cont amin ating ▁the ▁soil ▁and ▁the ▁ground water . ▁Since ▁mid ▁ 2 0 th ▁century , ▁large - scale ▁open - pit ▁min ing ▁comp ounded ▁matters , ▁causing ▁severe ▁land ▁de grad ation ▁in ▁vast ▁mountain ▁areas . ▁ ▁The ▁S ag unto ▁ore - processing ▁facilities , ▁Alt os