Writing about Gwernin Storyteller's travels requires detail. In the days before internet resources were available, I acquired topographic maps for approximately 80% of Britain, and still use them. Although I have visited most of the places I write about, some of those visits were over twenty years ago, and looking at the maps helps me remember them. Moreover, I have to image what those places would have been like in the 6th century! Nowadays, however, I do use Google maps to compute distances when figuring out how far Gwernin and his friends could ride (in a leisurely fashion) in a day.