Picture the map of Britain. Its strangely cadaverous shape, blobs of population and routes between them seem as familiar as our own faces; there is only one definitive map, surely? Not according to Joanne Parker, whose Britannia Obscura aims to tease out less corporeal cartography. Hers are not quite ‘maps of the mind’, for they exist as truly as a crisp new Ordnance Survey, but they are largely out of sight: above us, below us or otherwise in the shadows.
Each of her five chapters takes on a different map: of our cave and canal networks, overhead air routes and patterns of megalithic remains. These four are clearly real enough; the fifth, a map of ley lines, rather less certain. Yet they are all vague to most of us, and that is what interests Parker; like so many cartographers of old, she is hungry to map terra incognita.