Steve Duncan lives dangerously. The urban explorer goes underground, examining the hidden infrastructure of major cities all over the world — their tunnels, subways, sewers….http://www.npr.org/2013/09/14/222525583/new-york-underground-exploring-city-caves-and-catacombs?utm_source=buffer&utm_campaign=Buffer&utm_content=bufferce8c7&utm_medium=twitter