Adam Watson's interest in snow began at 7, the Cairngorms at 9, mountaineering and ski-mountaineering in later boyhood. His book recounts many fine days on the hill in Scotland, Iceland and northern Scandinavia on foot or ski, often on his own in wonderful places that excited him beyond measure. He tells what it was like to be with four remarkable Scots who greatly influenced him as a young naturalist and mountaineer, Seton Gordon, Bob Scott o the Derry, Tom Weir and Tom Patey. The beauty and variety of the hill, the weather and the wildlife were and are an inspiration to him, and his descriptions touch on this. In these modern times of pervasive regulation and politically correct control, this book is a breath of fresh air as a proclamation of the value and wonder that are the greatest joys of lone exploration on the spur of the moment. Author Adam Watson, BSc, PhD, DSc, DUniv, raised in lowland Aberdeenshire, is a retired research ecologist aged 80. He began lifelong interests on winter snow in 1937, snow patches in 1938, the Cairngorms in 1939. A mountaineer and ski-mountaineer since boyhood, he has experienced Scotland, Iceland, Norway, Sweden, mainland Canada, Newfoundland, Baffin Island, Finland, Switzerland, Italy, Vancouver Island and Alaska. His main research was and is on population biology, behaviour and habitat of northern birds and mammals. In retirement he has contributed 16 scientific publications on snow patches since 1994. He is a Fellow of the Arctic Institute of North America, Centre for Ecology and Hydrology, Royal Meteorological Society, Royal Society of Edinburgh, and Society of Biology. Since 1954 he has been a member of the Scottish Mountaineering Club and since 1968 author of the Club's District Guide to the Cairngorms. This book is testimony to the idea that Exploring for yourself by your own free will, without formal courses or training, is the best joy the hills can give (my Preface, The Cairngorms, 1975). Now I would add 'without detailed planning', for my best days have been lone trips begun without such planning, indeed on the spur of moment and weather, almost chance events. Four chapters salute Scots to whom I owed much as a young naturalist and mountaineer, Seton Gordon, Bob Scott, Tom Patey and Tom Weir. They held to the above idea. Reading Seton Gordon's Cairngorm Hills of Scotland in 1939 changed my life. I wanted to be in these hills at all seasons. Exploration by one's own free will is best pervaded by humility and wonder. Alien to this are avalanche alerts, 'challenge' walks, 'character-building', courses, Duke of Edinburgh Awards, guided walks, hill-runs, interpretive boards, marker cairns, outdoor centres, qualifications, rangers, route-cards, school outings, signposts, sponsored walks, tests of snowpack stability, text messages sent as avalanche alerts to mobile phones, transceivers, visitor centres, 'walk of the day', wardens, and 'wilderness walks'. Also alien are Munros, Corbetts and other anthropocentric designations, those who 'bag' them as if hills were shot birds, and assault, attack, battle, conquer, conquest, fight, vanquish and victory as if hills were enemies. Many with flashing camera, global positioning, map, compass, mobile phone, and survival equipment are unsafe, as rescue accounts often reveal. Even climbers have been rescued after neglecting navigation on easy ground after completing rock climbs or ice climbs. Those who behave as if alone on an icecap when nobody else knows where they are and no help is possible, have greater inherent safety. They are also more likely to understand and appreciate the hill and its weather, snow, wildlife and indigenous folk.