Back in the Cold War era, the Soviet-owned company Wismut ran massive mining operations in the East German states of Thuringia and Saxony. Thanks to the arms race, East Germany soon became the world’s third-largest uranium producer and a crucial supplier for Moscow. But when the USSR disintegrated, so did the market for uranium; with German re-unification, Russia sold its share of Wismut to Germany, leaving the country to orchestrate its most daunting post-Communist environmental cleanup. The $7 billion project involves filling and reforesting Europe’s largest open-pit mine, tamping and sealing 875 miles of shafts and tunnels, and cleaning up radioactive waste. The goal of the project? To return the economy of the region to its roots: farming in the Thuringia lowlands and tourism in Saxony’s once-scenic Ore Mountains region.