The International Union for Conservation of Nature (IUCN) published guidelines on sustainability for "Tourism and visitor management in protected areas". The publication is part of a series on best practices in protected areas and available for download on the IUCN website.
"Protected areas are a key component of any global conservation strategy. Tourism provides a crucial and unique way of fostering visitors’ connection with protected area values, making it a potentially positive force for conservation. Protected area tourism’s economic benefits - which depend on beautiful natural areas, healthy wildlife and nature, and authentic cultures - can also be a powerful argument for conservation. Tourism in protected areas is a major part of the global tourism industry - an industry whose scale and impacts are enormous. Such a high volume of visitors implies certain needs for fundamental infrastructure and requirements for employment and human services, all of which have ramifications for the economy, society, culture and the environment. These Guidelines provide guidance on key issues to help managers achieve sustainable tourism in protected areas."