All forms of tourism create environmental impacts, but these differ by orders of magnitude. At one end of the scale are minimal-impact wilderness travellers, either on foot or by water. These are permitted in many protected areas worldwide, and there is a well-tested suite of management and monitoring tools, summarised in this volume, to provide benefits to visitors without compromising primary conservation goals. At the other end of the scale are large-scale infrastructure, accommodation, and catering facilities, some of which can handle over a hundred thousand visitors a day.