A family harvests coca leaves in Santa Rosa, Peru. In the sacred valley of the Incas, cultivation of the plants is legal as long as farmers trade through Enaco (national coca enterprise), something they don’t entirely agree with because the state established company fixes prices and buys coca leaves at low rates. Carlos Villalón will be talking on 14 July. His book Coca: The Lost War explores coca as a sacred plant and cocaine through the failed war on drugs