Robert Macfarlane's extraordinary third book (his debut novel, Mountains of the Mind, was praised on its release and won several high profile awards) is part travelogue, part history and part philosophical treatise. It weaves together an exploration of wild places in Britain and Ireland with the stories of those characters, past and present, that have helped shape and define wildness.

The narrative (and the term is used loosely here) is an attempt to piece together an alternative map of the British archipelago. Not one that is bound by the usual atlas-lines of roads, railways and other human marks, but one that follows something almost more tangible: the rivers, mountains, rock and movement of animals. It sweeps down from the far north-west of Scotland, through the west coast of Ireland and eventually through the central part of England until it ends in an unlikely place; a quiet corner of Essex. Though all of his journeys put him at the edge, Macfarlane brings out the central stories of people that have shaped the landscape, making way for the wildness that has ultimately grown in these forgotten corners.

Macfarlane's language and art of description has the power of a particularly striking landscape photograph, portraying the scene in exquisite detail, but also adding in the stories and histories wrapped up in a particular scene. Throughout the course of the book he re-visits, over and over, his initial hypothesis of what constitutes wildness, and comes to an unexpected conclusion.

Not just a celebration of the beauty and power of wild places, there is also emotive descriptions of the challenge that wildness offers to a human. In particular, one dark and claustrophobic episode on the top of Ben Hope in the icy grip of winter reminds us that our understanding and ability to control wildness is tenuous and fleeting at best.

This is a fascinating book, brilliantly crafted, which I think will connect with many people's experience of the wild corners of these small islands. Although the scenes in Scotland were initially of most interest to me, I found that the episodes in Wales, Ireland and England expanded my appreciation for wild land and how it can be appreciated, both at a very close and personal level, and in a wider social and historical context.