Edgelands by Paul Farley and Michael Symmons Roberts - and I've discovered a new one. The Ridgeway in Plumstead is an elevated public footpath that runs the length of an victorian sewer.

What I like about these liminal spaces, they are a real halfway space where nature tries to reclaims concrete and metal but without fully succeeding, is that they allow you to see into industrial areas you don't normally have access to, into the backs of places where no-one is meant to see.  I also really like the way they don't really belong to anyone, though in theory the Ridgeway is owned by Thames Water, somewhere between no man's land and common land.