The establishment of a museum, natural park, biosphere reserve (the latter two generated without human intervention or merit) or any attraction open to visitors generates an increased flow or gradient of passage, as expected and desired by the promoters, stakeholders and collaborators of each project. However, there are limits to access and/or circulation that cannot be regulated or legislated, but are determined by the rules of nature and biology, namely the effects on the health, behaviour and sustainability of the species found there, which together will define the carrying capacity of each location.

There are several ways to manage visitor flow in order to preserve the balance between visitors and visited sites, implemented through transport schedules, opening hours, visitor quotas and/or any indicator resulting from intensity. Regarding the latter example, we find that animal welfare regulations are already at a much more advanced stage than those for human communities. These regulations are applied, for example, in theme parks or zoos, which temporarily close during the winter months or regulate visiting hours to ensure the welfare of their animals, respecting their rest, mating and recovery times.