Tourism brings a lot of joy to peoples’ lives, but it also brings suffering and certain sacrifices – to the natural environment, infrastructure, sites or even communities living close to the world’s most prominent sites. This year was declared the International Year of Sustainable Tourism for Development by the United Nations. As a result, this year Tourism-review.com focuses on tourism sustainability and the countries and sites that need to take necessary measures to sustain their tourism development. This time, we introduce the top destinations threatened by mass tourism.