Since its establishment in 2004, a total of 44 observatories have joined UN Tourism INSTO Network: 8 in China, 1 in Greece, 2 in Brazil, 5 in Indonesia, 1 in Croatia, 1 in the United States, 1 in Italy, 1 in Argentina, 1 in Australia, 4 in Portugal, 6 in Spain, 2 in Canada, 2 in Colombia, 1 in the Philippines, 1 in Japan, and the last to 2 observatories to join, 1 in Nuevo Leon and 1 in Peten, bringing a total of 4 in Mexico and 2 in Guatemala respectively.

The first observatories were established in 2006. While China led this early pioneering work, the network counts today a total of 44 destinations around the world that are passionately engaged in the continuous and timely measurement of the impacts of tourism, serving their stakeholders with up-to-date and reliable evidence for better decision making processes at the local level.

While it is mandatory to measure at least to some extend the eleven issue areas, each observatory is different in its structure and focus. Due to the context-sensitiveness of sustainability in general and the structures and characteristics of the destinations in specific, INSTO does not require members to specifically monitor pre-defined indicators, leaving enough flexibility in terms of the content and focusing more on the processes and innovative tools and techniques used by the destinations.