Sustainable Tourism has been a growing trend in the last couple of years and with it emerged several different certification and accreditation schemes promoting a sustainable way of travelling and spending the holidays. The book takes a closer look at what Sustainable Tourism is, why it is needed and how different forms of voluntary mechanisms like certification and accreditation schemes evolved within the industry. For this purpose it uses the theory of Global Governance and more importantly of Private Governance Systems as a framework. It illustrates on two different cases, namely the Green Globe and the Global Sustainable Tourism Council, what different types of voluntary mechanisms exist within the tourism industry, what their characteristics are and which factors fostered their emergence and development. This way the book not only contributes to the scientific debate about Private Governance Systems, especially in the field of sustainability, but moreover fosters and supports the transparent development of Sustainable Tourism.