Google Maps have a new toolkit, where you can create your own maps. We don't need much encouragement to play with such things, so soon put together a map of all our back passages. It differs from the previous Platial map in showing the extent of each alleyway, rather than just using place markers. The annotation tools on Google Maps are perfect for this kind of thing.
Google's map of London is not perfect, as we highlighted yesterday. One shortcoming is that many of the smaller alleys are not shown. Well that's where we come in. Each week, we'll continue to add to this overlay, and before long you'll have a map of alternative routes around the city.