Geoff Nicholson has been walking his whole life. Wherever he is and wherever he goes in the world, he walks and writes about what he sees and feels. Here he reflects on the nature of walking, why we do it, how it benefits us and, in some cases, how it can damage and even destroy us. Geoff's recent diagnosis with a rare, incurable form of cancer has made him all too aware of his own mortality. Sooner or later there will be a last step, a last excursion, a final drift, for him just as there will be for all of us. Geoff vows to continue to walk for as long as he can. This moving, vital book describes his own walks and relates them to the walks of street photographers, artists and writers, such as Garry Winogrand, Diane Arbus, Sophie Calle, Jorge Luis Borges and Virginia Woolf, among many others. Walking on Thin Air is a book about mortality and, above all, a celebration of being alive.