Boing Boing tipped me off to this NPR Interview about exploring the underground tunnels in NYC, and then I found this video about Steve Duncan (above). Fascinating, and totally bad ass.  Listen to the interview as well if you have time.

As an urban historian & photographer, I try to peel back the layers of a city to see what’s underneath. From the tops of bridges to the depths of sewer tunnels, these explorations of the urban environment help me puzzle together the interconnected, multi-dimensional history and complexity of the great metropolises of the world.