From Bethlehem to Belfast, Cyprus to Arizona to (topically) Spain's Moroccan enclaves, the Canadian writer tramps around the fences and partitions that separate folk who differ - or are assumed to - from close neighbours on the other side.
The book that results, packed with evocative stories of the folly of division, basks a little in (Canadian?) feelgood humanism. Some walls' foundations run deep.
But as a colourful, compassionate tour of hot spots where "nations stake territory in bald concrete", this beating of the bounds can't be topped.