Tourism is a rapidly growing industry with a far-reaching economic, social and environmental impact across the world. The rapid growth of tourism is a challenge for many destinations. More and more places struggle to cope with the impacts of high tourism intensities (overtourism). Since overtourism is a collective term that is used for many different challenges of tourism destinations, the situations can hardly be compared and defining general thresholds is not possible.The study seeks to explore the phenomenon by analysing interesting cases with indications of overtourism. The study will examine cases in several countries on different continents in order to analyse the applicability of different indicators. The goal is to identify the challenges of monitoring overtourism and to develop indicators that help to determine the phenomenon.