Minera Escondida (which means ‘hidden mining’ in Spanish) is a company that operates two open pit copper mines in the Atacama Desert, 170 km southeast of Antofagasta in northern Chile. It is currently the most productive copper mine in the world. Its 2007 production of 1,483 million tons of the metal was worth US$ 10.12 billion, mainly as metal in concentrate, but also as cathode. It stood for 9.5% of world output and 26% of Chilean production, according to the US Geological Survey’s preliminary estimates of 2007 world mine output.