You may not have heard of Baotou, but the mines and factories here help to keep our modern lives ticking. It is one of the world’s biggest suppliers of “rare earth” minerals. These elements can be found in everything from magnets in wind turbines and electric car motors, to the electronic guts of smartphones and flatscreen TVs. In 2009 China produced 95% of the world’s supply of these elements, and it’s estimated that the Bayan Obo mines just north of Baotou contain 70% of the world’s reserves. But, as we would discover, at what cost?