Some maintain that ley lines are the result of some "earth force," others that they are the earliest routes marked out across the land. In his new book Anthony Poulton-Smith examines the origins and meanings of these ancient trackways, tracing them on foot and taking in markers that have been in existence for millennia to travel in a straight line from Shropshire and Gloucestershire in the west to Cambridgeshire and Lincolnshire in the east. Whether...