It occurs to me that a very large amount of the fiction I read is set in London. I know the city vaguely, but I go a bit goggle eyed when authors start throwing around the borough names, because unlike say, New York, there's about a million of them, and they're hard to keep straight what's next to what and if it's north or south of the river.
So, in the spirit of Nevewhere and Matthew Swift, and the steampunk genre as a whole, here's a wonderful little map of a 5 mile radius from the central post office in London, of the official boroughs and where they are situated.
Also I just love that it's drawn in the style of a fantasy novel map (or rather, that fantasy novel maps are often drawn in this style). Oh you know what I mean, I think.
ETA: A few more London set books, courtesy Bookaneer (And one other I remembered myself, although it's not entirely set in London)