I remember once reading a novel (The Manhattan Hunt Club) where the story takes place in the tunnels under Manhattan. Not the levels where you take the subway, but further down and further in, where apparently transit workers and even New York’s finest dare not venture.
In this video, Andrew Wonder takes us on a brief journey down there, but not that deep as in the novel. We do not recommend that you try this on your own or on a whim because not only is the [third] rail electrified and you can get hit by a train, but also because there are real dangers lurking down there.
Read more at: http://www.undercity.org.