Today, tourism is an important component of development, not only in economic terms but also for knowledge and human welfare. Tourism today is an activity accessible to a growing number of people. The phenomenon has many more advantages than disadvantages. New forms of economic development and increasing wealth of human societies depend on tourism. Our knowledge of the world now includes a strong component due to tourism. Human welfare has physiological and psychological elements, which tourism promotes, both because of the enjoyment of knowing new territories and increasing contacts with near or far away societies and cultures. The tourism industry has nevertheless given rise to some serious concerns, including social costs and ecological impacts. Many ancient local cultures have practically lost their identity. Their societies have orientated their economy only to this industry. Both the natural and cultural - rural or urban - landscapes have also paid a high price for certain forms of tourism. These problems will persist if the economic benefit is the only target, leading to economic gains that eventually become ruinous. It is also important to consider that visitors nowadays are increasingly demanding in cultural and environmental terms. Never before have transport and communication links been so important as today. Natural ecosystems are now a rarity on the planet and ecologists talk today about 'socio-ecosystems'. Given this, tourism and environmental education are facing a major challenge. Tourism also plays an important role in the natural environmental changes that are strongly affected by technological and social developments. Natural changes are inherent in the Earth's ecosystem (the 'ecosphere'). Also, technological and social changes are inherent to mankind (the 'noosphere') and are now becoming widespread. Cities are growing rapidly and industry requires increasingly larger areas. Many traditional rural areas are being abandoned. However, many historic agricultural districts have maintained, or even recovered, their local population numbers through intelligent strategies of tourism focused on nature and rural culture. Natural landscapes and biodiversity are becoming increasingly appreciated. The tourism industry must be able to respond to these aspirations. The 9th International Conference on Sustainable Tourism had the aim of finding ways to protect the natural and cultural landscape through the development of new solutions which minimise the adverse effects of tourism. A selection of the papers presented at the meeting form this volume.