Armed with gloves, a backpack, and a healthy appreciation for the deadliness of the third rail, urban historian Steven Duncan and videographer Andrew Wonder explore the Undercity. This is the hidden New York. And it's beautiful. Wonder shot the compilation of urban explorationsappropriately titled Undercityon a Canon 5d Mark II. The journeys range from sewer to subway to Williamsburg Bridge, and give a look at the world that's happening underneath our feet, unbeknown to us, every single day. Duncan's made a mission out of these journeys, collecting his photographs and videos at Undercity.org.